Over the span of my pediatric career, there has been a slow trend in the way that parents view immunizations.  In medical school, I remember marveling at the pride in which parents or grandparents proclaimed that their child had all of his recommended immunizations.  I can remember particularly wondering why they felt so proud of this accomplishment (I had always received all of my shots) and it was not until later when I was in private practice that I realized that these parents and grandparents had sometimes made significant sacrifices in order to immunize their child.  At that time many people didn't have health insurance or had a type of health insurance such that they had to pay for their immunizations.  Hence, well child visits were somewhat of a luxury.  Times have changed.  Nowadays many people have health insurance that require only co-pays and immunizations are usually a part of that health insurance benefit or available at little to no cost at county health departments.  Despite the fact that immunizations are more readily available, many parents choose to forego or pursue a path of immunization that is not the recommended one.

 There are a lot of reasons for this, one being the rarity of which many of these preventable diseases occur.  When I was a child, there were several kids with whom I had contact that suffered from polio. A boy in the grade behind me order brace on his leg, a kid I swam with had a withered leg the size of his arm, and my cousin used braces and crutches because of polio.  I have some old family movies that show my cousin's family on Easter.  Her older brother and her younger sister scamper about looking for Easter eggs.  My cousin dressed in her Easter finery hobbles along as quickly a she could be using two braces to walk. Now as my cousin advances to middle-aged, she uses a wheelchair because of the weakness of her leg from polio 50 years ago.

 We don't see polio any more.  It is not in the forefront of people's minds as it was when I was little and some parents were afraid to allow their children go to public swimming pools in the summer because of the fear that their child may catch polio.  But to put things in perspective, currently we become alarmed when there are two or three cases of meningitis in the St. Louis area or when there are five or six cases of West Nile virus.  In 1955, less than 50 years ago, there were 36 deaths from polio in the St. Louis area in one summer.  If this happened today think of the alarm that it would cause.  Although polio is almost eradicated from the world, there are sufficient numbers of other diseases such as measles and pertussis that if  enough people decline immunizations these diseases may make a comeback.  In fact this has been seen both within our own country with measles and several other parts of the world within the last 20 years with pertussis.  Decreased immunization rates have resulted in outbreaks of measles and pertussis.

 Another  reason parents choose not immunize their children is the paradox of parents being better informed than years ago and seeking more information but at the same time being less or misinformed.  Parents crave knowledge.  They are concerned about past mistakes made with immunizations and the risk immunizations.  They try to be well-informed but in attempting to become better informed are often misinformed and misled by a very active anti-vaccination movement attempting to carve out its niche in the health-care world.  It can be very difficult for parents to sort out what is true and what is misleading.  Many  people opposed to immunizations claim  scientific research supporting immunizations is bad research and claim that they have good scientific research to support their claims against vaccines. As parents such claims can be difficult to sort out.  I would point out that most of the anti-vaccination literature is in the forms of books, essays, and web sites that the does not have the controlled scientific method with peer reviewed publications that mainstream medicine uses to evaluate and show the efficacy of immunizations.

 What is claim to be based on science is really not science at all—it is pseudoscience that can be a very convincing and misleading.  A common method is guilt by association.  For example, if a number of infants died with SIDS or crib death at 2 to 6 months of age and this is the age that they are receiving DPT vaccines then this must be the cause.  One anti-vaccination writer (Harvey Coulter A Shot in the Dark) claims that 1000 kids per year are killed by DPT shots. Another example would be the fact that autism is often identified surely after a child has received in MMR vaccination.  This particular  claim about the MMR will be discussed below, however, to use this type of logic in reverse I could make argument Hepatitis B shots (as well as DPT shots) protect infants from SIDS.  It has been shown that infants who are immunized with Hepatitis B at birth are less likely to die of SIDS than those who are not.  In fact, it has been shown that kids who are immunized--including DPT--are less likely to die of SIDS than those who are not.  However, I would not attempt to claim that DPT or Hepatitis B are SIDS preventing vaccines.  There are actually other factors which cause this apparent association.  The anti-vaccination movement, however, commonly seizes on unrelated coincidences and claims causal relationships. 

 The anti- vaccination movement has been very vocal, publishing snippets of studies and medical publications  that can be very misleading.  Some of the more common claims are that vaccines don=t  work, or that more  people get the diseases than those who are immunized.  Some claim that vaccines may cause the disease or  make it more likely to come down with the disease.  Two common claims aren't that the diseases were going away before the immunizations were introduced or that the diseases are gone and there is no further need to immunized against them.  The next couple paragraphs briefly address these.

The idea that more people get the disease when they are immunize than those adult is a shell game of numbers.  Let's use population of the Washington area to look at this.  Suppose there are 20,000 people in Washington that are immunized against a disease and the immunization is 95 percent effective.  Suppose also that 50 percent of people will either be exposed or that 50 percent of susceptible people who are exposed contract disease.  Of these 20,000 people in the Washington area who are immunized there would be 1000 immunized people whose body did not amount a sufficient response to be immune to the disease.  Hence if there were in outbreak in Washington, about 500 people who had received the shot would come down with the disease.  Suppose that there are about 1 percent or 200 people in Washington with chosen not to be immunized.  If the same rate of 50 percent of these people were exposed contract disease then the total number of people who were on immunized but who contracted disease would be about 100.  Obviously this is less than 500 so more people got the disease who were immunized.  However as you can see from this example claim that the vaccine didn't work is misleading.  95 percent of the people who got the vaccine were protected and only 2.5 percent of people who got the vaccine contracted the disease, however, 50 percent of people who decided not to get the vaccine got the disease.  .  Is important to realize that many of the childhood vaccine  preventable diseases have attack rates of over a 90 percent.  It is also important to know that there is a concept called herd immunity.  This means that if most people or animals in the herd are vaccinated and immune to the disease this offers some protection to those who are not vaccinated by preventing the spread of the disease.

 Commonly cited in the anti-vaccination literature alleging  that vaccines do not work is a statement about HIB vaccine alleging that it was only that 50% effective.  This citation was published in a journal called Pediatrics which is an important journal for pediatricians.  This is a true statement. There was one such study where the vaccine was only a 48 percent effective, however it is important to know the rest of the story.  This study was done on Navajo Indians in California using an older vaccine that we no longer use.  As a group these Native Americans have terrible problems with diseases from what is called encapsulated organisms such as HIB and pneumococcus.  This is  because genetically their  bodies do not  amount a resistance to the diseases even if they get the disease.  As a result many have problems with ear infections, meningitis, pneumonia and they get them recurrently because they have difficulty becoming immune to these disease.  Guess what, for that particularly vaccine,  they did not amount much of an immune response to it either and it didn't work very well for them (Based on what I just told you this should not be surprising)   The rest of the story, however, is that for the past 10 years we have been giving a newer HIB vaccine that has been incredibly effective.  In one year the number of cases of HIB disease went from 20,000 cases per year to less than 80. Or as another illustration, one hospital that averaged 121 cases of bacterial meningitis per year from HIB went to 3 the year after we started giving the shot to 2 month old.  Yet the antivaccination literature says that the HIB shot doesn't work and that the diseases were disappearing before the advent of vaccination. 

 HIB vaccine can be used as an example of two other common antivaccination claims.  One is that vaccines may actually cause the disease or make a person more susceptible--something that was very rarely  true for live oral polio vaccine (something that we no longer use) but also claimed about HIB.  Here again, medical literature is cited as the source.  It is true that when HIB first came out there briefly was a concern that giving the vaccine may temporarily make a child more susceptible to meningitis.  The medical literature which discussed this concern is commonly cited by vaccination opponents.  However, the rest of the story is that subsequent studies showed that this does not occur--something conveniently left out of their literature. 

 The second misleading claim is that vaccine preventable diseases were going away before vaccination programs were begun.  Commonly graphs are shown to suggest this and better hygiene, sanitation and nutrition are suggested as the cause.   There are a number of important things to keep in mind.  One is that the graphs may be showing death rates instead of prevalence rates.  Deaths from vaccine preventable disease were probably decreasing.  After all, hopefully advances in medical care in the 50s and 60s decreased the death rate.  Yet the incidence of the disease did not decline. In fact, in 1968--well after the decrease in polio and small pox--28,000 children were born blind from their mother's having rubella (today there are only about 6 cases per year, all of which occur in unimmunized immigrants).  There are a number of questions to ask those who claim that diseases were disappearing before vaccines were introduced:

1.                  If the diseases were disappearing, why were there outbreaks of measles in the 1980s after measles had almost been eliminated?

2.                  Since measles, rubella, rubeola, small pox, polio, and pertussis had greatly decreased, why did HIB disease persist until the introduction of shots to 2 month old infants in the 1990s? (Or for that matter, if HIB vaccine is ineffective as claimed by those against vaccines, why did the disease almost completely disappear one year after the decision to give HIB vaccine to 2 month old infants?)

3.                   If most vaccine preventable diseases had disappeared, why did chicken pox persist and why are we now seeing a decrease since the vaccine is required for licensed day care attendees and school?

4.                  If vaccine preventable disease were declining due to better hygiene, sanitation, and nutrition, why has polio almost been eliminated from the world given the desperate plight of many third world countries? Why did the only places (parts of the Soviet Union immediately after its break up)  we see increases in some disease be the places where there was a breakdown of government and distribution of vaccines?  Furthermore, several years ago when flooding in Central America destroyed much of their sanitation and clean water, why wasn't there an increase in polio?

 Most often, when confronted with the above statements, opponents of vaccination will change the focus or not respond.  This is a characteristic of the antivaccination movement.  In general, the approach it one of presenting a large number of unsubstantiated claims, shifting targets, and a strong anti-government, anti-pharmaceutical, and anti-traditional medicine bias.    This essay closes with the examination of two recent examples of this.