Archive-name: misc-kids/vaccinations/part2
Posting-Frequency: monthly
Last-Modified: February 11, 1996

===============================================================================
Section 3. Specific vaccines
-------------------------------------------------------------------------------
Section 3a. DTP (diptheria, pertussis, and tetanus) and DT

Q3a.1	What is diptheria, and what are the risks of the disease?

Diptheria is a contagious disease affecting the nose, throat, and
skin.  Complications include paralysis (about 20% of patients) and
heart damage (about 50%) (Pantell, Fries, and Vickery).  The Merck
manual has a very long list of complications, mostly involving the
heart, and says that complications are likely if antitoxin isn't
administered properly.  The death rate was 35% before antitoxin was
available, and is now 10% (Harrison).

Q3a.2	How common was diptheria before routine vaccination, and how
common is it now?

In 1900, there were 40.3 deaths per 100,000 population from diptheria 
in the US.  There was a sharp decline in the number of deaths per 100,000
both before and after routine vaccination was instituted in the 1940s, and
in 1990 there were 4 cases of diptheria reported in the US. (_Historical
Statistics of the United States, Colonial Times to 1970_ and _Statistical 
Abstracts of the United States_.

Q3a.3	How effective is the diptheria vaccine?

"The fatality rate in immunized populations is one-tenth that in the
unimmunized population.  Paralysis is 5 times and 'malignant' disease
15 times less common in immune than in nonimmune individuals."
(Harrison) 

Q3a.4	How long does the diptheria vaccine last?

Ten years.

Q3a.5	What is pertussis, and what are the risks of the disease?

Pertussis, or whooping cough, is a very contagious disease of the
respiratory tract.  Its attack rate in unvaccinated household contacts
is over 90% (PDR) or up to 90 and in some cases 100% (Harrison).

Pertussis is very serious in children under 2, with a mortality rate
on about 1 to 2%. (Merck)  "Prior to the availability of a vaccine,
pertussis caused as many deaths as all other contagious disease
_combined_." (Harrison, p. 607)  Complications include various lung
complications (The Merck Manual has a long list of these), cerebral
complications, hemorrage into the brain, eyes, skin, and mucuous
membranes.  In addition to killing, it can leave surviving infants
with lasting lung damage and neurological diseases.  

The mortality rate is higher in developing countries, partly because
children in these countries contract pertussis at a younger age (and
mortality is higher at younger ages), and partly due to an association
with protein-energy malnutrition (Galazka).  This same article estimated 
that in the industrialized world, 0.04% of infected children die from 
pertussis and complications, usually pneumonia  "Among vaccine-preventable 
diseases, pertussis rivals measles and neonatal tentanus in importance 
and severity in young children in developing countries and is third only 
to measles and neonatal tetanus as a cause of death.  It is estimated 
that pertussis is still causing some 340,000 deaths of children in the 
world each year." (Galazka)  

Q3a.6	How common was pertussis before routine vaccination, and how
common is it now?

"Since immunization against pertussis (whooping cough) became
widespread, the number of reported cases and associated mortality
declined from about 120,000 cases and 1,100 deaths in 1950, to an
annual rate of about 3,500 cases and 10 fatalities in recent years."
(PDR)  For unknown reasons, there has been an increase in the US recently.
"Over 6000 cases of pertussis were reported in the U.S.  in 1993, the 
highest number in 25 years." (N Engl J Med 1994 Jul 7; 331:16-21,
summarized in Journal Watch for July 22, 1994.)  There is also a 
recent report (MMWR Nov 11, p. 807) of a strain of pertussis
resistant to erythromycin.

In some other countries, pertussis is more common (most of the following
information is taken from Galazka).  "Before the introduction of
widespread immunization of young children with pertussis vaccine, the
incidence rates in Europe and the United States were very high.  The
reported rates per 100,000 population ranged from 200-300 in England and
Wales and Sweden, to more than 1,000 in Denmark and Norway." (Galazka)
Annual incidence in the US and Canada before the introduction of pertussis
vaccine in the 1940s ranged from 98 to 210 per 100,000 population.  After
the introduction and widespread use of DTP vaccine, incidence declined
dramatically in most countries, and this trend continued for about 20
years. For example, in England and Wales, more than 150,000 cases of
pertussis were reported a year in the 1950s; by 1973, when vaccine
acceptance was over 80%, only about 2,400 cases were reported. 

However, in the late 1970s and the 1980s, different trends began to 
appear in different European countries.  In one group of countries, 
reported incidence is between 10 and >100 per 100,000.  This group 
includes Sweden and Italy, which don't routinely give pertussis vaccine 
to infants.  It also includes Germany, the former USSR, Ireland, Spain, 
and the United Kingdom, where infants are routinely vaccinated, but 
coverage is less than 80%.  In Denmark, incidence is high despite high 
coverage, but Denmark uses a different vaccination schedule from the 
other countries.  Countries with a moderate reported incidence (between 1 
and 10 per 100,000) include Austria, Finland, Greece, Israel, Norway, the 
Netherlands, Portugal, Romania, and Yugoslavia.  Countries with a low 
incidence (<1 per 100,000) include Hungary, Switzerland, Bulgaria, 
Czechoslovakia, Poland, and Turkey.

Q3a.7	How effective is the pertussis vaccine?

It's one of the less effective childhood vaccinations.  The PDR
estimates its effectiveness at 70-80%.  It's effectiveness rating
depends on the severity of the cases of pertussis being observed.  One
study of 1797 households found the vaccine to be 64% effective against
a mild cough, 81% effective against a paroxysmal cough, and 95%
effective against severe clinical illness.  "Requiring laboratory
confirmation improved efficacy to 95 to 98% for culture-positive
children and to 77% to 95% for culture- or serology-confirmed cases,
depending on disease severity.  Vaccine efficacy for typical
paroxysmal cough increased from 44% for one diptheria, tetanus, and
pertussis vaccine to 80% for four or more doses." (Onorato, Wassilak,
and Meade)  The variation in estimates of efficacy may be because the
more severe cases were more likely to actually be pertussis, or it may
be that the vaccine protects better against severe pertussis than
against a mild form of the disease.

Q3a.8	How long does the pertussis vaccine last?

It doesn't.  According to _Harrison's Internal Medicine_, "the
protection ... is transient, with minimal resistance being evident a
decade later."  However, the critical years for pertussis immunity are
when a child is young; the disease is not dangerous for adults.

Q3a.9	What is tetanus, and what are the risks of the disease?

Tetanus is very dangerous.  Even with antibiotics, mortality can be 40% 
or higher (Pantell, Fries, and Vickery, Harrison).  Tetanus bacteria and 
its spores are everywhere.  Because tetanus is so ubiquitous, the only 
way to counter it is widespread vaccination.

*************************************************************************
From J Thompson (jet14@columbia.edu):

    The tetanus vaccine is actually against the tetanus toxin (a protein
called tetanospasmin), rather than the bacterium alone. The bacterium
doesn't really do much of significance, but the toxin it secretes can cause
muscular spasms. Thus, antibiotic therapy is rather pointless in preventing
the spasms, but it is given anyway. The administration of antitoxin (passive
immunity) is helpful. (see Harrison's, 13th ed., p. 635)
    The vaccine consists of what is called "tetanus toxoid," which is simply
 a purified version of the toxin, which has been treated to render it
ineffective as a toxin (but still immunogenic).
*************************************************************************

Q3a.10	How common was tetanus before routine vaccination, and how
common is it now?

300,000 to 500,000 cases are reported worldwide, with a mortality of about
45%.  In the US, there are about 100 cases a year, with a mortality of
40-60% (Harrison). 

Q3a.11	How effective is the tetanus vaccine?

According to Taking Care of Your Child, "Tetanus is one of our best
immunizations.... Of all the vaccines available, tetanus comes closest
to 100 percent effectiveness after the initial series of shots."

Q3a.12	How long does the tetanus vaccine last?

Generally ten years.  In the case of a really dirty wound, a booster
is recommended if the person hasn't been vaccinated for tetanus within
the last five years.

Q3a.13	What are some of the risks of the DTP vaccine?

DTP is probably the most controversial of the childhood vaccines,
because of risks associated with its pertussis component.  Anecdotal
evidence has linked the vaccine with a variety of problems, including
convulsions, physical collapse, brain damage and SIDS.  Supporters of
the vaccine have argued that these problems are common in any case at
the age at which children are vaccinated for pertussis, and therefore
are not necessarily effects of the vaccine.

The association between DTP and SIDS has not been confirmed by further
study (see Q1.5 for a study which found the evidence to be against such an
association).  The story on brain damage is somewhat different.  Criticism
of the pertussis vaccine received some confirmation in 1976, when a large
British study of all children 2 to 36 months old in Britain found that 1
in 310,000 doses resulted in permanent brain damage. 

Critics argue that the rate of complications from the pertussis
vaccine is too high, and the effectiveness too low.  Some argue that
the decline in pertussis cases in this century has been an effect more
of improved sanitation than of the pertussis vaccine.  The side
effects of this vaccine have inspired groups critical of vaccination
in several countries, including the US, where the group Dissatisfied
Parents Together (DPT) has lobbied Congress for changes to laws about
vaccination and set up its own vaccine information center.

Supporters of the pertussis vaccine differ in their response to the
British study which linked pertussis to brain damage.  Some say that
further analysis indicates that a link between the vaccine and brain
damage is not so clear.  "Meticulous reexamination of the data from this 
study led to the conclusion that the preliminary results were due to a 
systematic bias that favored finding an association between the vaccine 
and serious neurological sequelae.  In fact, there was no valid evidence 
from the study that the vaccine was associated with permanent 
neurological damage." (Shapiro)  

Some smaller studies done since the British study didn't find a connection
between DTP vaccine and neurological damage, and a new study was just
published in the Journal of the American Medical Association which finds
no increased risk of serious neurological illness.  I haven't seen the
article yet, so my information comes from the January 11, 1994 San Jose
Mercury (from the New York Times news service), which reports that the
study is in the current (as of 1/11/94) issue of JAMA.  According to the
article, "The federally financed study, the largest of its kind in the
United States, involved 218,000 children up to 24 months old in Oregon and
Washington who were studied for a one-year period, beginning Aug. 1,
1987." However, the study is also described as "not intended to give a
definitive answer to the question of whether whooping cough vaccine causes
neurological illness."

Others do not dispute the 1976 British study, but argue that a 1 in
310,000 risk of brain damage is still much smaller than the risk of
actually getting pertussis.  Supporters agree that it is important to
maintain high vaccination levels against pertussis, lest we see a
resurgence in the disease.  In Great Britain, Japan, and Sweden, there
were sharp increases in the number of cases of pertussis when vaccination
levels fell.  Routine use was discontinued in Sweden as a result of
reports of side effects, while acceptance in Great Britain declined to 30%
(Harrison), and vaccination declined in Japan as well.  "Within two years,
one hundred thousand cases (with twenty-eight deaths) appeared in Great
Britain and thirteen thousand cases (with forty-one deaths) in Japan. 
Even in the US, the disease has by no means been wiped out; there are
still about fifteen hundred to two thousand cases (with four to ten
deaths) each year. That is why virtually all health care authorities
recommend that we keep using this vaccine." (UC Berkeley)

Known and non-controversial (i.e. everyone agrees that they occur) side
effects of DTP vaccine include redness and tenderness at the injection
site, fever, drowsiness, fretfulness, vomiting, and convulsions. (A
vaccine information pamphlet from Kaiser gave the frequency as being 1 in
100 to 1 in 1000 for crying without stopping for three hours or longer, a
temperature of 105 F or greater, or an unusual, high-pitched cry, and 1 in
1,750 for convulsions, generally from high fever, or shock collapse.  I
didn't see any frequencies in the PDR, other than describing these side
effects as rare.) It is a good idea to give acetaminophen to children
being vaccinated for pertussis, to reduce the chance of fever and febrile
convulsions. 

From Mike Dedek:

*************************************************************************
American Journal of Diseases of Children 1992; 146: 173-176, February 1992, 
"Pertussis outbreaks in Groups Claiming Religious Exemptions to Vaccinations", 
Etkind, Lett, et. al.:

<my summary; 4 outbreaks between 1986 and 1988, although <= 1% of children
are not vaccinated, they provide pockets in which outbreaks can occur; 
schools containing >2% non-vaccinated students are monitored>
<direct quote follows>:
 Key measures in preventing pertussis are immunization and judicious use of
 prophylactic antibiotics.  Pertussis can be prevented in children by
 immunization.  Unfortunately, controversy over the safety of the pertussis
 vaccine has reduced acceptance.  Highly publicized accounts of reactions to the
 vaccine and a dramatic increase in the number of malpractice lawsuits have made
 physicians and parents wary of using the diphtheria-tetanus toxoid and pertussis
 vaccine. {n4-n6} This publicity may have caused overinterpretation of the
 guidelines for medical contraindications. {n7} However, this overinterpretation
 creates its own risk for malpractice if a child given an inappropriate medical
 contraindication suffers damage due to disease.
*************************************************************************

Q3a.14	When is the DTP vaccine contraindicated?

Hypersensitivity to a vaccine component, including thimerosal, a
mercury derivative.  Defer vaccination in case of fever or acute
infection (but not nececcarily for a mild cold without a fever).
A history of convulsions is generally a contraindication to
pertussis vaccination, but "The ACIP and AAP recognize certain
circumstances in which children with stable central nervous system
disorders, including well-controlled seizures or satisfactorily
explained single seizures, may receive pertussis vaccine.  The ACIP
and AAP do not consider a family history of seizures to be a
contraindication to pertussis vaccine." (PDR)

The following reactions to a previous dose are contraindications:
An immediate anapylactic reaction.  Encephalopathy occuring within
7 days following DTP vaccination.  Precautions include a fever of
>= 40.5 C (105 F) within 48 hours, collapse of shocklike state
within 48 hours, persistent inconsolable crying for more than 3 hours
within 48 hours, convulsions with or without fever within 3 days.
(These  latter are precautions rather than contraindications, because 
there might be circumstances, such as a pertussis epidemic, where you 
would still want to give the vaccine.)

Pertussis vaccine should not be given to anyone over seven years old.

Vaccine components capable of causing adverse reactions: for diptheria, 
thimerosal and toxoid; for tetanus, thimerosal and toxoid; for pertussis,
bacterial components (Travel Medicine Advisor).

Q3a.15	What are the advantages and disadvantages of the new acellular
pertussis vaccine?

The big advantage is that the acellular vaccine has fewer side effects. 
The FDA has held off on approving it for the earlier shots (while
approving it for the fourth and fifth shots), mainly due to remaining
uncertainty as to whether it is as effective as the whole cell vaccine.
Reports from Japan indicated that it is, but a Swedish clinical trial 
indicated efficacy of 59% for one, and 64% for the other acellular vaccine. 
However, even this trial did show >90% efficacy against severe pertussis. 
(Shapiro)  More recent results in Sweden and Italy indicate it is both
safe and effective.

As of 7/14/95, results are now available from two large European studies,
involving 9,829 infants in Sweden and 15,601 infants in Italy.  The
National Institute of Allergy and Infectious Disease (in the US) reported
that "three similar experimental vaccines effectively immunized 84% to 85%
of the children in the trials, while resulting in fewer side effects than
current, widely used versions." (Wall Street Journal, 7/14/95, p. A7A) A
surprising result of the studies was that whole cell pertussis vaccine
efficacy rates were lower than usual: "conventional vaccines provided
protection for just 36% of children in Italy and 48% in Sweden.  In the US
the conventional vaccine proves effective in 70% to 95% of the children
who are vaccinated."  Officials suggested that infants in these studies
might have had a higher intensity of exposure to the bacteria due to the
lack of widespread vaccination in those countries, and that might explain
the lower efficacy.  A fourth acellular vaccine provided protection in 58%
of the cases.  The high efficacy and low side effects shown for the
acellular pertussis vaccine in these studies will likely lead to requests
that the FDA also approve the acellular vaccine for the earlier pertusis
shots.  More information on recent study results can be found in NEJM, Vol.
333, Number 16, Oct. 19, 1995 (B. Trollfors and others).

From Mike Dedek:

This next one indicates there's a better vaccine that may soon become
available:

*************************************************************************
In Pediatrics 1992; 89; 882-887, May 1992, "Acellular Pertussis Vaccination
of 2-Month Old Infants in the United States", Pichichero, Francis, et. at.:

ABSTRACT: This is the first study in children from the United States that
evaluates the immunogenicity of and adverse reactions to the Connaught/Biken
two-component acellular  pertussis  vaccine compared with whole-cell  pertussis
vaccine when given as a primary immunization series at 2, 4, and 6 months of
age.  Three hundred eighty infants were studied; 285 received acellular
diphtheria-tetanus toxoids- pertussis  (DTP (ADTP)) and 95 received whole-cell
DTP (WDTP).  Following the third dose, ADTP vaccination produced higher antibody
responses than WDTP to lymphocytosis-promoting factor (enzyme-linked
immunosorbent assay IgG geometric mean titer (GMT) = 131 vs 9 and Chinese
hamster ovary cell assay GMT = 273 vs 16) and to filamentous hemagglutinin (IgG
GMT = 73 vs 10) (all P < .0001).  Agglutinin responses were higher in WDTP
compared with ADTP recipients (GMT = 50 vs 37; P = .02).  Local reactions were
fewer for all three doses following ADTP vaccination.  Fever, irritability,
drowsiness, anorexia, vomiting, and unusual crying all occurred less frequently
in ADTP compared with WDTP recipients for one or more of the three doses.  We
conclude that this two-component ADTP vaccine when given as a primary series
produces greater immunogenicity and fewer adverse effects than the currently
licensed WDTP vaccine.

...A large case-control study
in Britain (National Childhood Encephalopathy Study) estimated that permanent
neurologic deficits may occur after its administration in 1 in 310000 doses
of WDTP.  However, a reanalysis of this and similar studies recently has led 
to the widely held conclusion that a causal association between WDTP vaccination
and permanent brain damage has not been demonstrated....

*************************************************************************
Public Health Rep 1992; 107: 365-366, May 1992/June 1992, "FDA Approves New
Whooping Cough Vaccine"

    The Food and Drug Administration (FDA) has licensed a  new  whooping cough
 vaccine  that may cause fewer side effects in children.

    The  new vaccine  is being approved at this time only for the fourth and
 fifth shots.  The current vaccine will continue to be used for the first three
 shots.  Additional research has been undertaken to ascertain whether it will be
 effective for preventing  pertussis  when used for primary inmunization -- the
 first three shots -- in infants.

   The  new vaccine  is acellular, meaning that it is made from only part of the
 pertussis  organism, as opposed to the whole organism from which the current
 vaccine is derived.

   Whooping cough ( pertussis)  is a highly contagious disease.  As many as 90
 percent of nonimmune household contacts acquire the infection.  Since routine
 immunization against  pertussis  became common in the United States, the number
 of reported cases of disease and deaths from it has declined from about 120,000
 cases with 1,100 deaths in 1950 to an annual average in recent years of about
 3,500 cases with 10 fatalities.

   The  new vaccine  appears to be as effective in older children as the current
 vaccine and to cause fewer adverse reactions.  It has been widely used in Japan
 -- where it was developed -- with apparent success in children older than 2
 years.  It will be combined with diphtheria and tetanus toxoids (DTP) and sold
 under the brand name Acel-Imune.

   Gerald Quinnan, MD, acting director of FDA's Center for Biologics, where the
 vaccine was evaluated and licensed, said that the availability of an acellular
 vaccine is a significant step forward in infectious disease control.

  The most common adverse reactions seen in clinical trials of the acellular
 pertussis  vaccine included tenderness, redness, and swelling at the injection
 site, fever, drowsiness, fretfulness, and vomiting.

  The  new pertussis vaccine  component is produced by Takeda Chemical
 Industries Ltd. of Osaka, Japan, and is combined with diphtheria and tetanus
 toxoids manufactured by Lederle Laboratories of Wayne, NJ.  Lederle will also
 distribute the product in the United States.  The vaccine is administered by
 injection.

  The approval of the  new vaccine  comes at a time when the Federal Government
is emphasizing early childhood immunizations in the wake of the largest reported
measles outbreak in the nation in 20 years -- with more than 27,600 cases and 89
deaths reported in 1990.

  The aim is to reach a goal of full immunization for 90 percent of children by
 the time they are 2 years old.
*************************************************************************

Q3a.16	What are some of the risks of the DT (diptheria and tetanus)
vaccine?

Most of the risk in the DTP vaccine comes from its pertussis component;
the diptheria and tetanus vaccines are quite safe. Reactions to the
diptheria vaccine are quite rare.  Most reactions are local, limited to
swelling at the injection site.  The same is true of the tetanus shot. 
"Severe local reactions can occur if too many shots are received; this
phenomenon was frequently seen in military recruits who received unneeded
immunizations." (Pantell, Fries, and Vickery)

Q3a.17	When is the DT vaccine contraindicated?

Should be avoided during the first trimester of pregnancy.  People
who have had a reaction (which is very rare) should avoid it.

Vaccine components capable of causing adverse reactions: for diptheria, 
thimerosal and toxoid; for tetanus, thimerosal and toxoid (Travel Medicine 
Advisor).

Q3a.18	Under what circumstances is tetanus toxoid given to pregnant
women? 

Tetanus toxoid is given to pregnant women in countries where there is
a high risk of neonatal tetanus (due to factors which enhance the risk
of cord contamination in these countries).

===============================================================================
Section 3b. Polio

Q3b.1	What is polio, and what are the risks of the disease?

Polio is a contagious viral disease which crippled tens of thousands
in the 1950s, and killed more than a thousand a year.  Because it is a
mild gastrointestinal illness in young children and a serious
paralytic illness in older people, it had an unusual epidemiology,
with more cases of paralytic polio turning up in wealthy areas and as
sanitation improved.  80-90% of cases of polio are the minor illness;
the rest are paralytic poliomyelitis.  In paralytic poliomyelitis, <
25% suffer permanent severe disability, about 25% have mild
disabilities, and > 50% recover with no residual paralysis.  Mortality
is 1 to 4%.  "Recently, a post poliomyelitis syndrome has been
described, characterized by muscle fatigue and decreased endurance...
The syndrome occurs many years after an attack of paralytic
poliomyelitis..." (Merck).

Q3b.2	How effective is the polio vaccine?

The Merck Manual and the Physician's Desk Reference give its
effectiveness as 95%.  An article in a WHO publication (Hull and Ward)
estimates effectiveness at 80%.  (As with other WHO estimates, the
lower effectiveness rating reflects an estimate of effectiveness in
the field in a variety of countries, including countries in the Third
World.  Polio vaccine effectiveness can deteriorate if it is exposed
to too much heat, which can happen in vaccination programs in some
countries.) 

Q3b.3	How long does the polio vaccine last?

It provides lifelong immunity.

Q3b.4	What is the difference between oral polio vaccine (OPV) and
inactivated polio vaccine (IPV)?

Oral polio vaccine provides better immunity, and is usually the
recommended form, "because induces intestinal immunity, is simple to
administer, is well accepted by patients, results in immunization of
some contacts of vaccinated persons, and has a record of having
essentially eliminated disease associated with wild poliovirus in this
country." (PDR)  However, it carries a small risk of paralysis (see
the answer to the next question for details).

Q3b.5	I've heard that it is possible to contract polio from handling
the diapers of recently immunized infants.  How long after receiving
the vaccine does the child's excrement continue to contain the virus?

*************************************************************************
From Caren Feldman:

> Speaking of this, I know there has been mention in the past of contracting
> polio from handling diapers of recently immunized infants.  Does anyone
> know how long after receiving the vaccine the child's excrement continues to
> contain the virus?  The reason I ask is because sean got his polio booster
> and Rachel has only received the first vaccine in the series.  The doctor's
> office said she wain no danger of contracting poliofrom him since they don't
> come in contact with each other *that* closely.  However, I have to be extra
> careful after helping Sean clean up (he needs help sometimes) or handling his
> underwear to make sure I wash my hands thoroughly.  So, how long until I
> can stop being paranoid about remembering to wash my hands after handling
> the laundry?  (I forgot to ask)
> 
The short answer is 6 weeks. But since you brought up the subject...here's what
I fond out about polio immunizations:

When I had read one poster's response that the live polio virus from feces
was actually weakened virus that would in fact help immunize unimmunized kids
they'd come in contact with it, naturally I didn't believe it. Well, not at
first. But I had enough doubts of my disbelief to start asking around, and came
up with some (at least to me) little known facts about polio and polio
immunizations. I am presenting it to misc.kids for everyone's edification.

Indeed, live virus from a recently immunized child's feces is weakened virus
that health officials actually hope unimmunized kids  come in contact with to
provide them with individual immunity and the general population with "herd"
immunity.

Now here's the tricky part. One of the attenuated strains used to make the
vaccine has a very low but existing back mutation rate, back to the "wild
type", i.e. back to "regular" polio. If the weakened virus the child has been
given mutates back to wild-type polio, any adult with no immunity to it (or
an immunized adult for whom the immunization series did not "take") is
potentially at risk for full blown polio. Of course, people with weak immune
systems may be at risk even from  weakened virus. Steroid use may also cause
the immune system to weaken (besides the usual anti-rejection drugs, HIV,
leukemia) and thus increase susceptibility for contracting the virus.

Polio in young children manifests itself as a mild gastrointestinal ailment.
Polio in older children and adults starts as a mild gastroenteritis but with
complications that may lead to paralysis. Before the advent of improved public
sanitation, most young children were exposed to and probably contracted the
polio virus, so by adulthood, chances were everyone had immunity to it. It
was only when public sanitation improved to where exposure to the virus was
delayed until later childhood that polio epidemics became prevelant. Polio
outbreaks in the US were less frequent among poor children than among more 
affluent families.

The CDC estimates the chances of getting polio from a first immunization (I
presume this means gastroenteritis symptoms in babies, not paralytic polio)
is one in half million. The chances of getting polio from subsequent
immunizations is 1 in 12 million. I assume the chances of secondarily
contracting polio from feces are even rarer.

These rare cases probably account for the supermarket tabloid (not to mention
"60 Minutes") stories of adults catching polio from recently immunized kids
who'd been given oral vaccine. For those in the US, you will be glad to
hear that a federal compensation program exists, called the National Vaccine
Injury Compensation Program, to help those stricken with paralytic polio as a
result of coming into contact with a recipient of the oral polio vaccine.


Thanks go to two posters on sci.med for answering my questions regarding this
subject.
*************************************************************************

The 1993 Physician's Desk Reference confirms Caren Feldman's account,
with two small modifications.  First, it gives the time when the virus
is shed as 6-8 weeks, rather than six.  Second, the CDC estimates which
she gives are the estimates for cases of paralysis in *both* vaccine
recipients and contacts of vaccine recipients combined, not for recipients
alone.

Q3b.6	What are some other risks of the polio vaccine?

A small risk of anaphylactic shock.

Q3b.7	When is the polio vaccine contraindicated?

Because of the small risk of paralytic polio in recipients and contact
of recipients of OPV, it should not be given to anyone who is
immune-compromised or who has immune-compromised family members.  (The
PDR has a really long list of immune deficiencies involved, which you
can check if you think anyone in your family falls in this category.)
In these cases, IPV should be given instead.  IPV is also recommended
for adults who are at risk for polio (such as unvaccinated adults
travelling to an area where polio is endemic).  Both vaccines are 
contraindicated for people with an anaphylactic allergy to neomycin or 
streptomycin.

Vaccine components capable of causing adverse reactions: for both OPV
and IPV, streptomycin, neomycin, and phenol red; for IPV, animal
protein, formaldehyde, and polymyxin B (Travel Medicine Advisor).

Q3b.8	Isn't it true that wild polio has been eliminated in the US?

From Mike Dedek:

*************************************************************************
>From The Reuter Library Report, 2/26/93, "U.N. Warns on need for Polio 
Immunisation" copyright 1993 Reuters:

 The last  outbreak of polio  took place in the Netherlands 15 years ago. The
 virus was carried to Canada and the United States by infected people visiting
 their relatives, the WHO said. This caused the United States' last  polio
  outbreak  which hit the Amish community in the state of Pennsylvania in 1979.

*************************************************************************
>From The [London] Independent, 2/9/93, pg. 12, "Why child vaccines may be a
shot in the dark", by Tessa Thomas:

 After numerous  cases  in which the ''live'' oral  polio  vaccination was
 found to have caused the disease, the American government is considering
 reintroducing the inactivated injectable version. In the UK, the Department of
 Health advocates the live version on the basis that it deactivates any wild
 polio  virus that reaches the gut, preventing it being excreted into the
 community, thus conferring community protection. The injectable vaccine acts
 only on the bloodstream, protecting the individual but not breaking the chain of
 infection. Lobbying by the Association of Parents of Vaccine Damaged Children
 has prompted an acknowledgement by Virginia Bottomley, the Secretary of State
 for Health, that the live vaccine is responsible for 50 per cent of recent new
 cases of polio.  Between 1978 and 1991 there were 42  cases of polio,  18 of
 which followed vaccination and nine of which followed infection through contact
 with the vaccinated child.

*************************************************************************
The Atlanta Journal and Constitution, 12/19/92, "Cases in Netherlands put
Americas at risk for polio", by Steve Sternberg, Section E; pg. 1

  The last polio case in the Americas emerged on Aug. 23, 1991 in the remote
  Peruvian highlands village of Pichinaki...

*************************************************************************
UPI 12/10/92:

  Except for a few rare vaccine-associated  cases,  there have been no  cases
  of polio  in the United States since 1986 when there was one imported  case.
  The current vaccine, Sutter said, is close to 100 percent effective in
  preventing the disease.

*************************************************************************

Q3b.9	Why are we still vaccinating for polio, then?

The AAP and ACIP continue to recommend vaccination for polio for
several reasons.  First, the risk of the disease is much higher than
the risk of the vaccine.  Second, though there is no wild polio in the
US *now*, with high levels of vaccination, there is still polio
elsewhere in the world.  148,000 cases were reported to WHO in 1990.
China reported 5,065 cases.  The USSR reported 337 cases.  India
reported 7,340. (Hull and Ward)  There have been several outbreaks of
polio in countries 2 or more years after the last reported case of polio.
Importation from polio endemic countries has led to outbreaks in Oman
(1988-89 and 1993), Jordan (1991-92), Malaysia (1992), and the Netherlands
(1992-93) (MMWR, reported in HICNet Medical News on 15 August 1994).  
Wild poliovirus type 3 was isolated during January-February 1993 among
members of a religious community objecting to vaccination in Canada
(although no actual cases of parlytic polio occurred in Canada at this
time).  There is a concern that if levels of vaccination were reduced in 
the US, polio could be reintroduced, and we could see polio epidemics here 
again.

Encouraged by the worldwide elimination of smallpox, WHO, in 1988, set
a goal of eradicating polio from the world by 2000.  Since then, the
number of cases in the world has declined dramatically (29,916 in 1989
and 16,435 in 1990), and the number of countries reporting 0 cases has
increased (74 countries in 1985 and 116 countries in 1990).  As of 1993,
the number of cases worldwide has falled to 9714, and nearly 70 percent
of all countries reported no cases. (Progress toward global eradication of 
poliomyelitis, 1988-1993. MMWR 1994 Jul 15; 43:499-503.  Summarized in 
Journal Watch Summaries for July 22, 1994.) So another factor in the 
decision to continue vaccinating for polio is the hope that it can be 
eliminated for good.

There has been discussion in the US about switching to IPV instead of 
OPV for some doses (IPV being less effective, but lower in side effects).  
The decision at first was to continue with OPV because it has been so 
successful, the rate of side effects is still considered very low, and 
because of various advantages in producing immunity (see above).  
According to the 1993 PDR, "The choice of OPV as the preferred poliovirus 
vaccine for primary administration to children in the United States has 
been made by the ACIP, the Committee on Infectious Diseases of the American
Academy of Pediatrics, and a special expert committee of the Institute
of Medicine, National Academy of Sciences."  In 1995, though, that decision
was changed, and we will soon see the use of the injected vaccine for the
first two polio shots. 

===============================================================================
Section 3c. MMR (measles, mumps, and rubella)

Q3c.1	What is measles, and what are the risks of the disease?

Measles is one of the most contagious infectious diseases. "A child can 
catch measles by breathing the air in a doctor's waiting room two hours 
after an infected child has left." (Fettner)  90% of susceptible 
household contacts get the disease (Harrison).  Measles spreads very 
rapidly in unexposed populations.  In 1951, it was introduced to 
Greenland by a recently arriaved visitor who went to a dance as he was 
coming down with it, and in three months it spread to more than 4000 
cases and 72 deaths.  The attack rate was 999 cases per 1000 people. In 
1875, measles was introduced to Fiji and killed 30 percent of the 
population (Smith).

In areas where it was endemic, before the measles vaccine, measles 
epidemics used to occur at regular intervals of two to three years, 
usually in the spring, with small local outbreaks in intervening years.  
Mortality is low in healthy, well-nourished children unless complications 
ensue (Merck), but nevertheless there were 400 deaths a year before an 
improved measles vaccine was introduced in 1966 (Pantell, Fries, and 
Vickery).  Complications include brain infection, pneumonia, convulsions, 
blindness, various bacterial infections, encephalitis, and SSPE (a fatal 
complication which can occur years after a person has had measles).  
Pregnant women who get measles have a 20% chance of miscarriage.

Worldwide, measles is one of the leading causes of childhood mortality.  
"Measles has been called the greatest killer of children in history." 
(Clements, Strassburg, Cutts, and Torel)  In 1990, "45 million cases and 
around 1 million deaths were estimated to occur in developing countries.  
Thus measles is still responsible for more deaths than any other EPI 
target diseases. The true number dying as a result of measles may be 
twice the estimated 1 million if the recently documented delayed effect 
of the disease is taken into account." (Ibid.)  Mortality is higher in 
developing countries due to a difference in the age at which most people 
catch it (measles is a more dangerous disease in the very young), poorer 
nutrition, less availability of treatment for bacterial chest infections, 
and other environmental factors.  However, "Even in countries with 
adequate health care and healthy child populations, the complication rate 
can reach 10%." (Ibid.)

More information on the incidence of measles complications is found in 
the answer to Q3c.2.

Q3c.2	How common was measles before routine vaccination, and how
common is it now?

*************************************************************************
From Anthony C.:

I havent finished reading this thread so pardon if someone else has
already posted this information

Rates of complications of measles and measles immunization
			Measles per 10^5 Vaccine per 10^5
Encephalomylelitis	50-400		.1
sspe			.5-2.0		.05-.1
Pneumonia		3800-1000	
Seizures		500-1000	.02-19
Deaths			10-10000	.01

These statistics are worldwide, hence the variablility in numbers.  The
higher rates of pneumonia and death represent figures collected from
India, Nambia, Nigeria, bangladesh and other countries with developing
health care industries.

As far as the number of people afflicted with measles in the US
	Cases		Deaths
1963	385,566		364 	Inactivated measles type vaccine available
1964	458,093		421
1966	204,136		261	public health administration of vaccine
1967	62,705		81
1968	22,231		24
.
.hovers around 20-70,000
.
1977	57,345		15
1978	26,871		11
1979	13,597		6
1980	13,506		11
1981	3,032		2
1982	1,697		2
1983	1,497		4
1984	2,587		1
1985	2,822		4
1986	6,273		2
1987	3,588 		2
1988	2,933		not available
1989	16,236		41
1990	26,520		97

iMajor foci of retransmission barring the complete elimination of measles:
1) unimmunized indigent, inner city youngsters.
2) illegal aliens.

I hope this is useful.  My source is Zinsser microbiology, 20th edition
pages 1013-1015, joklik et al.
*************************************************************************

Measles has been on the decline again in the US since 1990 (MMWR Feb 4,
1994, p. 57).  Colleges enforcing the requirement for a second measles
vaccine report fewer measles outbreaks than schools with no requirement
(JAMA, Oct 12, 1994, p. 1127).  (Both of these citations from Journal
Watch for Jan 15, 1995 - paper edition, or Feb 7, 1995 - electronic
edition.)

Q3c.3	How effective is the measles vaccine?

The Merck Manual and the Physician's Desk Reference estimate its
effectiveness at 95%.  This estimate is based on studies of the
immunity induced by a series of vaccinations beginning at 15 months.
Another article, estimating the immunity induced in field conditions
(including some Third World countries, which may have less reliable
vaccine storage) by a series of injections beginning at 9 months (the
injections are started earlier in areas where measles is widespread),
estimated effectiveness as 85% (Clements, Strassburg, Cutts, and
Torel). 

Q3c.4	How long does the measles vaccine last?

The Merck Manual describes it as "durable."  The PDR says that all of the 
antibody levels induced by MMR have been shown to last up to 11 years 
without substantial decline, and "continued surveillance will be 
necessary to determine further duration of antibody persistance."

Q3c.5	What are some of the risks of the measles vaccine?

There is a small chance of complications similar to the complications of 
measles (pneumonia, encephalitis, SSPE).  Information on the frequency of 
these complications is included in the answer to Q3c.2. There is some 
risk of anaphylaxis for people allergic to eggs or neomycin.

Q3c.6	What is mumps, and what are the risks of the disease?

Mumps is a viral disease which is less contagious than measles or chicken 
pox.  It causes swollen salivary glands.  The most common complication is 
swelling of the testes (in about 20 percent of males post puberty) and, 
less commonly, ovaries.  Rarely, it can lead to sterility.  Other 
complications are meningitis (less common than in measles) and acute 
pancreatitits.  (A much longer list of complications can be found in the 
Merck Manual.)

Q3c.7	How common was mumps before routine vaccination, and how
common is it now?

105,00 cases were reported in 1970; by 1990 the rate of reported cases 
was down to 5,300.

Q3c.8	How effective is the mumps vaccine?

The Merck Manual estimates its effectiveness at 95%.  The Physician's
Desk Reference gives its effectiveness as 96%.

Q3c.9	How long does the mumps vaccine last?

The Merck Manual describes it as "durable." "Mumps immunization provides
protection through the blood serum antibodies for at least 12 years, and
possibly much longer." (Pantell, Fries, and Vickery) (See also Q3.4 for
the PDR's description of the duration of all the MMR-induced antibodies.)

Q3c.10	What are some of the risks of the mumps vaccine?

"Rarely, side effects of mumps vaccination have been reported, including 
encephalitis, seizures, nerve deafness, parotits, purpura, rash, and 
prurittis." (Merck. Encephalitis and convulsions were also on Merck's 
list of complications for mumps itself.)

Q3c.11	What is rubella, and what are the risks of the disease?

Rubella is a mild illness, consisting of a mild fever and rash.  Rare 
complications include ear infections and encephalitis, but the real 
danger is to pregnant women.  During the last rubella epidemic, in 1964, 
20,000 children were born with birth defects caused by rubella.  Birth 
defects include deafness, cataracts, microcephaly, and mental 
retardation.  Children born with congenital rubella are als susceptible 
to rubella panencephalitis in their early teens.

Q3c.12	How common was rubella before routine vaccination, and how
common is it now?

Before the development of the rubella vaccine, epidemics used to occur at
irregular intervals in the spring, with major epidemics at 6 to 9 year
intervals.  (This means that one was just about due when the vaccine came
out in 1969.) There have been no major epidemics since 1969, but the
number of cases of rubella and congenital rubella syndrome increased
starting in 1989 (Merck, also California Morbidity for November 19, 1993). 
(It was still a small fraction of the pre-vaccine number, though, see table
of disease frequencies in section 1.)  "Serological surveys conducted in 
the late 1970s and the 1980s indicated that 10 to 25 percent of United 
States women of child-bearing age were shown to be susceptible to 
rubella." (California Morbidity, November 19, 1993)  It now appears to be
declining again: "Following a resurgence of rubella and congenital rubella 
syndrome (CRS) during 1989-1991, the reported number of rubella cases during 
1992 and 1993 was the lowest ever recorded." (MMWR, cited in June 9, 1994 
HICNet Medical News Digest.)

Q3c.13	How effective is the rubella vaccine?

The Merck Manual estimates its effectiveness at 95%.  The Physician's
Desk Reference gives its effectiveness as 99%.

Q3c.14	How long does the rubella vaccine last?

The Merck Manual describes it as "sustained." (See also Q3.4 for the PDR's
description of the duration of all the MMR-induced antibodies.)

Another reference, from Heather Madrone:

*************************************************************************
D. M. Horstmann "Controlling Rubella:  Problems and Perspectives"
_Annals of Internal Medicine_, vol. 83, no. 3, pg. 412

Horstmann found reduced antibody formation 3-5 years after administering
the vaccine and 25% of those tested showed no immunity to rubella at
all.
*************************************************************************

Q3c.15	What are the pros and cons of vaccinating all infants for
rubella versus vaccinating females only at puberty?

There is still some uncertainty about the most desirable rubella 
vaccination policy.  In 1969, when the vaccine came out, it was decided 
to avert the expected epidemic by vaccinating all children over one year, 
so that they would not spread rubella to their possible pregnant mothers 
- the first time one group of people was vaccinated to avoid having them 
spread a disease to a different group of people.  Supporters of this 
policy point out that the expected epidemic didn't occur.  The possible 
disadvantage is that we aren't sure how long the immunity lasts.  Now 
that generation of children is old enough to have children, and some of 
them may no longer be immune.  In the past, 80% of the population was 
immune due to having had rubella in childhood.

Some countries follow a policy of vaccinating girls at puberty if they
don't have rubella antibodies (Pantell, Fries, and Vickery).  The
disadvantage is that vaccine side effects are more common at this age. 
The most common is joint pain, which occurs in 10% of women who are
vaccinated in adolescence or later.  In some cases, it has lasted as long
as 24 months.  (Pantell, Fries, and Vickery) The PDR describes this same
side effect in somewhat milder terms, saying that it generally does not
last very long and "Even in older women (35-45 years), these reactions are
generally well tolerated and rarely interfere with normal activities." It
does agree with Pantell, Fries, and Vickery that the incidence of this side
effect increases with age: 0-3% of children and 12-20% of women have joint
pain, and the pain is more marked and of longer duration in the adult
women.  A few women (between 1 in 500 and 1 in 10,000) experience
peripheral neuropathy (tingling hands).  Another risk of vaccinating later
is the risk that a woman may be pregnant.  So far, no connection with
birth defects has been demonstrated, but women are advised to avoid
pregnancy for three months after getting the vaccination. 

Current US policy is to vaccinate all children at 15 months, and give a 
booster during school years.  Adult women are advised to get an antibody 
test before becoming pregnant, and, if it comes up negative, get 
vaccinated and wait three months before getting pregnant.

There has not been a rubella epidemic since 1964, either in countries 
which vaccinate all children at 15 months, or in countries which 
vaccinate girls only at puberty.

Q3c.16	What are some of the risks of the rubella vaccine?

The PDR has a long list of possible adverse reactions (besides arthritis
and arthralgia, usually short-lived, see above).  Most of them are either
mild or rare. 

Q3c.17	When is the MMR vaccine contraindicated?

People with an anaphylactic or anaphylactoid allergy to eggs or neomycin 
should not get the vaccine.  Other allergies or chicken or feather allergies
are not a contraindication.  Vaccination should be deferred in case of
fever.  The PDR give active untreated tuberculosis as a contraindication,
but the AHFS says that there is no evidence of a need to worry about TB.
Both give immune deficiency as a contraindication (see PDR for a long
list of immune deficiencies involved).  Immune globulin preparation or 
blood/blood product received in the preceding 3 months.  The same 
contraindications apply individually to measles and mumps vaccines, but 
the rubella vaccine can be given by itself to people with an anaphylactic 
egg allergy.  The other contraindications still apply to the rubella 
vaccine alone.  (California Morbidity, October 31, 1987)

Vaccine components capable of causing adverse reactions: for mumps
and measles, chick fibroblast components; for mump, measles, and
rubella, neomycin (Travel Medicine Advisor).

===============================================================================
Section 3d. HiB (Hemophilus influenze B)

Q3d.1	What is hemophilus influenze B, and what are the risks of the
disease? 

HiB is a bacteria which is one of the leading causes of meningitis in 
young children.  About 60% of cases are meningitis.  The remaining 40% 
are cellulitis, epiglottis, pericarditis, pneumonia, sepsis, and septic 
arthritis.  Mortality rate can be about 5%, and there are neurologic 
sequelae in up to 38% of survivors.

Q3d.2	How common was HiB before routine vaccination, and how
common is it now?

Before routine vaccination, about 12,000 cases a year in the US, with a 
cumulative risk of 1 in 200 that a child would get the disease by age 5.  
A vaccine was introduced in 1985.  Since the introduction of the Hib conjugate 
vaccine in 1988, the race-adjusted incidence of Hib among children less than 5, 
has declined from 41 cases per 100,000 in 1987 to two cases per 100,000 in 
1993.  (The incidence for people five or older remained stable.  Hib is most 
serious in children under 5.)  (A decline of 95%, despite the fact that the 
National Health Interview Survey showed only 67% of children 12-23 months 
had received at least one dose, and 36% three or more doses.  This decline 
is attributed to the elimination of carriage, which reduces Hib exposure 
even in unvaccinated children.) The CDC has a goal of eliminating Hib in 
the US by 1996.  (HICN708 Medical News, "[MMWR] Progress Elimination 
Haemophilus influenzae type b")

Q3d.3	How effective is the HiB vaccine?

Estimates from different labs vary a lot.  AHFS Drug Information,
after noting this variability, and the uncertainty as to what antibody
level is adequate for protection, says that in one study, 75% of
children 18-23 months and 85% of children 24-29 months had serum
anticapsular antibody levels of one microgram per milliliter or
greater.  The PDR lists numerous studies, with results ranging from
100% efficacy to one study in which vaccinated children had more cases
of HiB than the unvaccinated group.  With the exception of the latter
study, all of the studies showed significant positive results, often
with efficacy estimates over 90%.

According to a NY Times article of 12/18/90, HiB vaccine produces
lower antibody response among Native Americans, but the new conjugated 
vaccine seems to produce higher antibody response in Native  American
children and may protect all children at a younger age.

Q3d.4	How long does the HiB vaccine last?

The duration of immunity is unknown.  However, the disease is only
dangerous to very small children.

Q3d.5	What are some of the risks of the HiB vaccine?

In a study of 401 infants, fever occurred in 2%, and redness, warmth, or 
swelling in 3.3%.  All adverse reactions were infrequent and transient. 
(PDR) 

Q3d.6	When is the HiB vaccine contraindicated?

Hypersensitivity to any component of the vaccine, including diptheria 
toxoid and thimerosal in the multi-dose presentation.

Vaccine components capable of causing adverse reactions: phenol,
bacterial polysaccharides, thimerosal (Travel Medicine Advisor).

Q3d.7	What about rifampin prophylaxis?

An alternative to HiB vaccination is rifampin prophylaxis, but it
could be unwieldy to administer.  AHFS Drug Information says that it
is "effective for eradicating nasopharyngeal carriage of HiB, but the
efficacy of the drug for prevention of secondary disease has not been
firmly established."

===============================================================================
Section 3e. Hepatitis B gamma globulin and hepatitis B vaccine

Q3e.1	What is hepatitis B, and what are the risks of the disease?

There are several forms of hepatitis, infections of the liver which 
cause jaundice, nausea, and weakness.  Hepatitis B is spread mainly by 
contact with infected blood and by intimate contact with bodily fluids, 
such as in sexual intercourse and childbirth.  However, the hepatitis
B virus is far more resilient than, for example, the AIDS virus, and 
the disease is not strictly a venereal disease, and can be caught even 
by people who are not sexually active.  Hepatitis B becomes chronic
in 5-10% of those infected.  Complications include hepatic necrosis,
cirrhosis of the liver, chronic active hepatitis, and hepatocellular
carcinoma.  Hepatitis B is endemic throughout the world, and a serious
problem in groups at increased risk.  Information about hepatitis B
is available by calling 1-800-HEP-B-873.  Another source of information
about hepatitis B and many other forms of liver disease is:

           American Liver Foundation
           1425 Pompton Avenue
           Cedar Grove, NJ  07009

A source on hepatitis B in particular is:

	Hepatitis B Coalition
	1537 Selby Ave  #229
	St Paul, MN 55104
	(612) 647-9009

There is also a hepatitis mailing list, HEPV-L on LISTSERV@SJUVM.STJOHNS.EDU.  
A Web page on Diseases of the Liver can be found at 

	http://cpmcnet.columbia.edu/dept/gi/disliv.html 

A US government source of information on hepatitis is:

	Hepatitis Branch
	Mailstop G37
	CDC
	Atlanta, GA 30333
	or call the CDC Automated Voice Information System at (404) 332-2553.

Hepatitis B should not be confused with hepatitis A, which is more
contagious but less serious.  Hepatitis A is spread through contaminated
food and water.  Symptoms can be mild flulike symptoms or severe nausea
lasting for weeks.  Hepatitis A does not become chronic and is rarely
fatal.  Other forms of hepatitis include hepatitis C, hepatitis D, and
hepatitis E, and hepatitis (being a general term for inflammation of
the liver) can also be caused by certain medications.  Information on
other kinds of hepatitis can be obtained from the American Liver
Foundation.

Q3e.2	How common is hepatitis B?

"The estimated lifetime risk of HBV infection in the United States
varies from almost 100% for the highest risk groups to approximately
5% for the population as a whole." (PDR)  The CDC estimates about
0.75 - 1 million chronic carriers in the US, and more than 170 million
are estimated worldwide.

Q3e.3	What is hepatitis B gamma globulin, and when is it given?

It is given to people who have already been exposed to hepatitis B, to
boost their immunity.  In particular, it is given to children born to
mothers with hepatitis B.  It should be given as soon as possible
after birth for the best results.

Q3e.4	How long does the immunity provided by hepatitis B gamma
globulin last?

Two months, maybe longer.

Q3e.5	What are the risks and contraindications of hepatitis B gamma
globulin? 

No known contraindications.  A couple of diseases (see PDR for more
information) are listed under precautions (a weaker form of warning than
contraindication - in the case of precautions gamma globulin may be given, 
but the extra risks of giving the gamma globulin have to be weighed against 
the benefits).  These diseases, though, aren't ones a newborn is likely to 
have, so they would probably not apply in the case of giving it to 
the newborn of a mother infected with hepatitis B.  

Q3e.6	How effective is the hepatitis B vaccine?

It varies depending on the age, sex, and general health of the
recipient.  About 96-100% in infants and children 19 and under, 94-99%
in adults 20-39, 88-91% in adults 40 or older.  May be lower in men
than women.  Lower (only 64% in one study) in hemodialysis patients.
(AHFS Drug Information 1992)  The PDR estimated 95-96% for infants,
and agrees with AHFS about the conditions which reduce effectiveness.

Q3e.7	How long does the hepatitis B vaccine last?

There is evidence that immunity lasts up to ten years, but beyond that,
the duration is uncertain, and the need for booster doses not defined. 
(My source for the duration is Journal Watch, 9/1/93.)

Q3e.8	What are some of the risks of the hepatitis B vaccine?

"During clinical studies involving over 10,000 individuals distributed
over all age groups, no serious adverse reactions attributable to vaccine
administration were reported." (PDR)  The most common adverse reactions 
were injection site soreness (22%) and fatigue (14%).  A longer list of
adverse reactions can be found in the PDR.

Q3e.9	When is the hepatitis B vaccine contraindicated?

Sensitivity to yeast or any other component of the vaccine.
Pregnancy is not a contraindication to hepatitis B vaccination. 

Vaccine components capable of causing adverse reactions: aluminum
phosphate, thimerosal, and formaldehyde (Travel Medicine Advisor).

Q3e.10	Why did the ACIP and AAP change their recommendation about the
hepatitis B vaccine?

Up until 1992, the recommendation was that hepatitis B vaccine be given 
only to people in high risk groups for hepatitis B: people whose 
professions exposed them to blood, people at extra risk due to their 
sexual practices or intravenous drug use, and certain populations (such 
as Southeast Asian immigrants) with a high incidence of the disease.  The 
chief reason was cost; it was felt to be not cost-effective to vaccinate 
low-risk groups.

Unfortunately, this policy was not successful in checking the spread of 
hepatitis B.  It proved difficult to identify high-risk people, and 
high-risk people did not volunteer in large numbers to be vaccinated.  
For this reason, in 1992, the ACIP recommendation was switched to 
vaccination of teens and adults in high-risk groups and universal 
vaccination of infants.  The AAP made a similar recommendation but would 
also like to extend hepatitis B vaccination to all adolescents, if possible.

The American Liver Foundation also supports hepatitis B vaccination of
infants, and their pamphlet on the subject suggests a variety of ways
in which even young children could come in contact with the virus (through
contact with blood, etc.).  Though young children are at low risk of
catching hepatitis B, their risk of developing the chronic form of the
disease if they do catch it is higher than for adults.

The new policy was well-received internationally, and 30 countries now 
have universal infant HBV vaccination programs.  Many physicians remain 
skeptical, however, and a survey in North Carolina showed one third of 
pediatricians and <20% of family physicians supporting the new guidelines 
(Journal Watch, 9-1-93).  (Update: Journal Watch for Jan 15, 1995/Feb 7, 
1995 reports that this vaccine is gaining physician acceptance, citing
Arch Pediatr Adolesc Med Sep 1994, p. 936)

Why the resistance? One reason is a reluctance to give low-risk infants 
yet another vaccination.  Another is doubt about the duration of HBV 
vaccine.  There is evidence that it lasts up to 10 years, but we do not 
know yet whether it wears off beyond that point.  There is concern that 
infants vaccinated for HBV may lose immunity during adolescence, when the 
risk of catching the disease is greatest.  An alternative would be to 
vaccinate all children at age 10 and give a booster at age 20.  But 
compliance would likely be lower at age 10 than in infancy.  Hepatitis B
vaccine is administered in three shots over the course of six months, and
it would be difficult to get preteens to all come in for the full series.  
Also, 8% of hepatitis B infections occur before age 10, and the deadly
form is three times greater in children (NY Times, 3/3/93:B8).  Boosters 
could be given later to infants vaccinated for HBV if immunity proves to 
lapse.

Hepatitis B vaccine is also often recommended for travel purposes.

Q3e.11  Does vaccination for hepatitis B affect one's ability to
donate blood?

*************************************************************************
From Gregory Froehlich, MD (from a posting to sci.med):

First, hepatitis B *antigen* is used to make Hep B vaccine.  The
antigen is grown in yeast culture; formerly, it was purified from the
blood of people who were chronic hepatitis carriers. Antibodies are
used in the gamma globulin shots used for hepatitis A or for passive
immunization against hepatitis B if you're exposed.

The local blood bank does not specifically test for exposure to
hepatitis A (the kind you'd get from contaminated water).  If a person
has an active hep A infection, it will be picked up by elevated liver
enzymes; if the person had such an infection in the past, it's over and
done with--hep A doesn't give you a chronic, subclinical infection.
Antibodies to hepatitis A should not preclude blood donation.

They check for chronic hep B carriers by testing for hep B surface
antigen.  They test for recent hep B infection by testing for hep B
core antibody.  This antibody does not carry disease, but rather
indicates that the person was recently infected and might or might not
still be infectious.  They do not test for surface *antibody*, which
would indicate either (a) former hep B infection which was cleared, or
(b) immunization against hep B--in either case, not infectious.  I've
got hep B surface antibody, because I was immunized; I can still donate
blood.

Blood banks also test for hepatitis C antibody; people with this
antibody can still be infectious.
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Q3e.12  Do people who have showed up positive on the blood banks' tests
for hepatitis B exposure still need to be vaccinated?

It is still useful to be vaccinated, because some of the people who show
up positive on the blood bank tests are false positive.

Q3e.13  I will be travelling to an area where hepatitis B shots are
recommended, but I have less than six months before I leave.  Is there
an accelerated schedule for hepatitis B vaccination?

_Travel Medicine Advisor_ lists an accelerated schedule, with 3 doses
at 0, 30, and 60 days.  With this schedule, a fourth dose is recommended
at 12 months if there is still a risk for hepatitis B exposure.

