As an unfortunate legacy of the now discredited Wakefield
“study” in many areas of the country, it has become too common that parents are
opting out of vaccinating their youngsters before entering kindergarten. The
negative consequences for their children is obvious, but for the school and the
community as a whole the results can be quite significant. While some parents
are legitimately opting out of vaccinations for medical, religious or
philosophical exemptions from vaccinating their children. In the cases where
parents have a sincerely held religious belief that prohibits vaccinations,
those beliefs need to be respected; that is the small minority of cases.
Similarly some children must not be vaccinated, either because
they have medical conditions or have had adverse reactions which contraindicate
their receiving vaccinations. These
children depend upon what is known as herd immunity to protect them against
serious if not lethal cases of contagious but preventable diseases. To achieve herd immunity, a critical mass of
the population must be vaccinated, usually about 95% depending on the illness
being vaccinated against. At this level,
disease transmission is contained because it cannot be transferred. Outbreaks of disease, however, can occur in
areas where this threshold is unmet, and those individuals who are not
vaccinated; e.g., the young, the immunocompromised, the medically vulnerable,
or those who are vaccinated but for whom the vaccine is not working, all become
at risk.
A recent study published by the Journal of Infectious
Diseases examined how unevenly the 50 states allow medical exemptions from
required vaccinations. The researchers,
Stadlin et al., compiled data over a seven-year period. Nationally, in the 2004-2005 school year, 11,277
kindergarteners received medical exemptions.
That number increased to 13,952 in the 2010-2011 school year. A total of 87,631 students received medical
exemptions over the study period. The
number of medical exemptions decreased in states which had more stringent
criteria for their use. Conversely, in those states in which it was somewhat
easy to receive exemptions based on philosophical or religious grounds, the
rate of medical exemptions also was decreased.
In those states in which it was more difficult to receive exemptions
based on philosophical grounds, the rate of medical exemptions increased,
strongly suggesting that medical exemptions are being used for children in whom
vaccinations are not contraindicated.
The study researchers state that it is known that
immunization exemptions occur in geographic clusters. Some of the lowest vaccination rates are
occurring in the northwest, including parts of Oregon, Washington, Idaho, and
Montana. In fact, a public health
official characterized Oregon as the “black hole” of religious exemptions. In 2011 5.6% of entering kindergarteners had
religious exemptions, an increase of 2% from ten years ago.
As a result of these clusters, we are seeing outbreaks of
disease. California is experiencing
an outbreak of pertussis. Last year
there were 7,297 known or suspected cases in the state, which is a fourfold
increase from 2009. By 2010, the number
of pertussis cases exceeded 9,000.
It is clear how this is happening:
in some Bay-area schools, more than 40% of students are
unvaccinated. Marin County, which had
350 cases in 2010, has appeared to stem the outbreak by offering vaccination
clinics and requiring all middle and high school students to have up-to-date
vaccinations. Last November 900 Marin
county residents were vaccinated, and only 10 new cases were reported in the
first nine months of 2011.
A 2008 measles outbreak in San Diego began with an
unvaccinated 7-year-old who picked up the disease in Switzerland before passing
it on to an infant in the pediatrician’s office and three classmates. Overall, 11 unvaccinated children were
infected. Another measles outbreak
occurred in Indiana when two people with measles visited a crowded Super Bowl
venue, resulting in 12 measles cases.
Parents have become anxious about vaccines as the result
of the now-debunked Wakefield study, which purportedly found a link between
vaccinations and autism. Even though the
Lancet, which published the study, ultimately retracted it and deemed it
fraudulent, and even though Dr. Wakefield went on to lose his license, some
parents are still refusing to vaccinate their children out of fears of autism. Other parents object to the number
of shots their children are receiving by kindergarten or to their side
effects. Ultimately, however, parents
who choose to not vaccinate their children are placing them at risk of
developing diseases such as measles, which has a 90% infection rate in
unvaccinated people.
The good news is that in some areas, vaccination rates have
begun to increase, perhaps in response to the swine flu epidemic, in which
vaccines were in short supply, even for high-risk groups, and horrified and
panicked parents watched otherwise healthy children succumb to the disease. In 2010, the national rate of vaccinations for
MMR was 91.5%, up from 90% in 2009 but still short of reaching the critical
mass for herd immunity to be in place.
A companion piece to the Stadlin study in the Journal
of Infectious Diseases chastises medical providers who are allowing
unnecessary medical exemptions, which not only results in failing to protect
those who cannot be vaccinated, but also serves to increase unnecessary anxiety
about the safety of vaccines overall.
The authors urge physicians to follow the vaccination recommendations
from the Centers for Disease Control and Prevention, the American Academy of
Pediatrics, and the American Academy of Family Physicians. To not vaccinate children undermines the
efforts to control or prevent entirely these vaccine-preventable diseases. Clearly, visiting the pediatrician for those
vaccinations needs to be returned to the back to school to-do list for parents.
It is time for parents to rely on sound science and medicine to make decisions,
not outdated and discredited studies that have unleashed significant harm from
preventable diseases.