It is necessary to allow these PBEs. There are children who are medically fragile or who have a history of serious reactions to vaccines, including dangerously high fevers or seizures. Certain religious groups may be opposed to vaccination. All of these children should have the right to go to school. However - and this is a big however - unvaccinated children should be the rare exception.
In my mind, that means just a few kids each year. But we can put a real number on this. From a public health perspective, we need to maintain high enough levels of immunity in the population so that diseases cannot spread. This is often called "herd immunity."
The concept of herd immunity is important to understand. A large percentage of a population needs to be inoculated against contagious diseases to keep those diseases from spreading. This ensures that those who do not have immunity are less likely to come in contact with someone who has the disease. The herd immunity rate is different for each disease, but range from 80-95%.
There is a wide variance in the herd immunity, even for a single disease. The actual level of immunity needed will vary depending on the specifics of the outbreak, including the effectiveness of the vaccines and closeness of the social network. A classroom would be a very close social network. Have you ever experienced a lice outbreak? It can spread pretty fast, and that requires actual physical contact. Ever see a cold go through a class? Last year, one cold took out half of Moe's class in one week. Imagine if that cold were measles or polio; it would be devastating.
The CA Department of Public Health publishes the vaccination rates for kindergarten classes in California. I looked at the 2010 rates of PBEs. At Moe's school, 5% of kids in kindergarten have exemptions. That's pretty good. An outbreak of most diseases would likely be contained quickly. This was the highest number of PBEs in all of our district.
The district we'd like to move to, however, has one school with a 16% PBE. That means only 84% of kids in kindergarten at that school are fully vaccinated. That is dangerously low. A major outbreak could definitely occur.
A few other schools in neighboring districts had similarly frightening rates of exemptions:
- McAuliffe School: 12%
- Leroy Anderson Elementary: 22%
- Simonds Elementary: 30%
- Casa di Mir Montessori: 20%
- German International School: 36%
- Waldorf School Los Altos: 76%
What is most interesting to me about these numbers is that many of the schools with the lowest rates of vaccination are at the schools with well educated parents who think they are doing the right thing for their children. They think they are enlightened because they question "big pharma" (who, by the way, only makes 1.5% of their profits from vaccines). They "trust their instincts" about vaccines, believing that so many vaccines must overwhelm their little babies' immune systems. But most parents can't possibly have an instinct about this. They aren't trained to evaluate risk. It is why we have science, and the evidence overwhelmingly tells us vaccines are safe.
Q: If everyone else is vaccinated, why does it matter if I don't vaccinate my child?
A: First, your child could come into contact with someone else who has the disease. It only takes one. Second, each child matters. If a class has twenty kids, it only takes 3 unvaccinated kids to drop below herd immunity levels. But be aware, even if your school has a 95% vaccination rate, that means at least 5% of the kids are at risk, but probably more. Herd immunity levels may contain a major outbreak, but any unvaccinated child could still get sick. Third, you are not just putting your child at risk. Your child could infect someone else, including a child too young to have received the vaccine.
Q: If vaccines aren't 100% effective, why should I put my child at risk for the possible side effects of the vaccines if he isn't going to be protected anyway?
A: Vaccines are not a guarantee against the disease. Yes, a child can get a vaccine and still get the disease, but it is much less likely. Even so, when most people are vaccinated, any given person is much less likely to come in contact with someone else who could infect him.
The risk of the vaccines themselves are very low. For example, according to the CDC, a person who gets measles faces the following risks:
- Pneumonia: 6 in 100
- Encephalitis: 1 in 1,000
- Death: 2 in 1,000
But the risk of major side effect of the MMR vaccine (encephalitis or severe allergic reaction) is literally one in a million.
Q: We use other ways to fight disease, like healthy eating, exercise, and dietary supplements. Isn't that enough?
A healthy lifestyle is important. I don't want to underestimate that. A strong immune system helps fight off or lessen the effects of many diseases, especially common colds and flus. But as one person in my mom's group said, "when measles comes around the Burger King eating, obese, never sees the daylight, TV-addicted, vaccinated kid will NOT get it and your kids WILL. It is a biological fact."
Please, please, please vaccinate your children. It is the right thing to do.