This post originally appeared on the Disease Daily on Aug 25, 2014. It has been republished here with permission from the authors.
In our last myth-busting post of the month, we’re taking on the impression you might get from reading blogs or news online about vaccines: that droves of parents are deciding not to vaccinate their kids anymore. We know that with all the anti-vaccine chatter on social media or in the news, it often feels like everyone and their next-door neighbor is delaying, cherry-picking, or downright refusing vaccines.
But vaccination is very much still the social norm. In 2012, among US children ages 19-35 months, 92.8 percent were fully vaccinated against poliovirus. Ninety-four percent were vaccinated against diphtheria, tetanus, and pertussis (three diseases prevented with the DTaP shot). Overall, 80 percent completed three important childhood series: DTaP, polio, and MMR.
If the majority of kids ARE getting vaccinated, why do we seem to only hear about those who aren’t? It’s a case of a silent majority versus a very vocal minority.
The fact is that nationally, vaccination coverage is relatively high — but not high enough. We need exceptionally high immunization coverage against exceptionally infectious diseases, like measles. And worst of all, national averages can hide some local variances that create dangerous powder kegs for infectious disease outbreaks.
For example, in California in the 2007-2008 school year, 92.1% of kindergarteners were fully immunized — not bad, right? Well, unfortunately it’s not that simple. Someplace like Glenn County reported 98.5% immunization rates — you go, Glenn Co! But… on the other hand, Nevada County reported that just 75.5% of its kindergarteners were fully immunized. That’s not high enough to ensure herd immunity against many diseases, like measles or whooping cough. One infectious traveler entering that under-protected community could be the spark to start an outbreak.
One potentially overlooked factor is why those kids are not fully immunized. And here the story gets a little more nuanced. There’s a big difference in being unvaccinated and undervaccinated. Unvaccinated children haven’t received a single vaccine; undervaccinated children have received one, some or even most of the vaccine schedule but are still missing some important shots. And it turns out these two groups are pretty different.
Researchers looked at a random sample of over 20,000 children, from 1995-2001 to learn a little more about those two groups of children. What they found was that only 0.3 percent were completely unvaccinated (here’s that vocal minority– these parents were more likely to report concerns around vaccine safety). It’s actually an incredibly small amount of people who are refusing all vaccines (good news!).
But… over 35 percent of children were undervaccinated to some degree. These children were statistically more likely to be racial or ethnic minorities, have a mother with low educational attainment, and live in poverty. These likely aren’t kids whose parents are refusing to let them get vaccinated, but they might be having trouble seeing a provider regularly or paying for vaccines. They’re falling through the cracks of the health system. This group is arguably the most important group for public health officials to focus on for outreach and more services.
Almost everyone IS vaccinating. But to keep it that way, the silent majority needs to get louder about their support for vaccination.
Jane manages the Vaccine Finder project at Health Map, the host site of the Disease Daily. Robyn is a contributing writer for the Disease Daily and works as a project manager for a non-profit focused on vaccine education. Both are fully up-to-date on their immunizations.