As soon as writer eula biss began working on her new book, she found herself embroiled in arguments on an online parenting forum and angering other mothers she knew. She was, after all, writing about an act that, in some circles, is considered highly contentious: taking her son to get his routine vaccinations.
Biss’s book, On Immunity: An Inoculation, published this month by Graywolf Press, coincides with another event likely to refuel the local vaccination debate: On September 1, new state laws expand vaccination mandates. Seventh graders, for example, will be required to get inoculated for meningitis and receive a booster for pertussis, and children participating in early-childhood programs will be required to be vaccinated against hepatitis A and hepatitis B.
But the new rules aren’t universally followed: Minnesota is one of 20 states that allows exemptions for both religious and personal beliefs. While non-medical exemptions have increased nationwide through 2011, statewide vaccination rates for MMR, DTaP, and varicella still hover at about 96 percent. “That number kind of lulls us into a false sense of reassurance,” says Mark Schleiss, MD, director of the Division of Pediatric Infectious Diseases at the University of Minnesota. “People may think, ‘Oh well, 95 percent is good enough.’ But what if that one child is your child who develops a lifelong disability or dies?”
Mistrust of vaccines is as old as vaccination itself, the history of which Biss outlines in her book. In the mid-18th century, cowpox inoculation was found to protect against smallpox after it was observed that farmers and milkmaids rarely contracted the more-lethal disease. But when Britain passed a smallpox vaccination law in 1853, it birthed the first anti-vaccination movement, when people were concerned about the contents of the inoculations. While vaccines are not free from adverse effects, Biss says, that statistically minute risk must be weighed against the harm of the diseases they’re designed to protect against. “While every vaccine tragedy that I looked into was awful, rarely were there as many [deaths] as the disease that was being vaccinated against,” she says.
Members of Minnesota’s anti-vax community are taking the new legislation in stride. “As long as parents know that their decisions to vaccinate their own children with all, some, or none of the ‘required’ vaccines are based on personal medical/health reasons and not just to get into school, I have no problem adding more vaccines to the ‘required’ collecting list,” says Christina Abel of Vaccine Awareness Minnesota. “But how many parents really know and understand their rights?”
And how many who choose not to vaccinate, scientists counter, fully understand the consequences of those decisions, not only for themselves, but for the community? Herd immunity—when most people are vaccinated and diseases disappear because there are so few people left to infect—requires certain percentages of the population to be immunized in order to work (exact numbers vary based on the disease). One benefit is protection for the population’s most vulnerable: newborns, for example, and the elderly. By that rationale, getting a flu shot isn’t just about avoiding that feverish chill; it could help the immuno-compromised co-worker, or an older family member.
Even though the state’s 96-percent vaccination rate would seem to meet the threshold of herd immunity, the 4 percent of unvaccinated Minnesotans aren’t evenly distributed throughout the state. They tend to be clustered in like-minded communities of the kind that come to national attention when outbreaks occur: the vaccine-shy megachurch in Texas where measles broke out, for example, or the whooping cough outbreak that sickened 9,120 people and killed 10 babies in California, in which data showed strong correlation between cases of the illness and areas with high rates of personal-belief exemptions.
Or in Minnesota, where fears that the MMR vaccine causes autism contributed to a plunge in vaccination rates among the Somali community from 91 percent in 2004 to 54 percent in 2010. A recent medical study showed that, in 2011, a 2½-year-old unvaccinated child who had contracted measles on a trip to Kenya unwittingly exposed 3,000 Minnesotans to the disease before being diagnosed; without herd immunity, measles sickened 21 people, 16 of whom were not vaccinated.
One thing both sides of the debate can agree on is eradication of disease, a milestone smallpox reached by 1980. “The goal of any vaccination program is to reach the stage where you don’t need to give it to anyone,” Schleiss says.
