Observations Yankee Doodling

Jabbering about jabs

BMJ 2008; 337 doi: https://doi.org/10.1136/bmj.a1517 (Published 03 September 2008) Cite this as: BMJ 2008;337:a1517
  1. Douglas Kamerow, chief scientist, RTI International, and associate editor, BMJ
  1. dkamerow{at}rti.org

    Why are rates of immunisation of children now falling in the US?

    As an American, one of the (few) things about the US healthcare “system” that I have always taken pride in is our ability to fully vaccinate virtually all of our children by the time they start school. When I was growing up, before measles vaccine, thousands of cases of measles encephalitis and hundreds of measles related deaths occurred every year in the United States. By the turn of the current century, though, vaccination programmes had eliminated endemic measles, and the few remaining cases reported in the US were related to travel and immigration.

    Not so in Europe. Vaccination coverage is low in several European countries, leading to ongoing outbreaks. And in the United Kingdom in June the Health Protection Agency announced that, because of declining vaccination coverage, measles had again become endemic in England and Wales (BMJ 2008;337:a1254, doi:10.1136/bmj.a1254).

    Because it is so contagious, measles is a great harbinger of vaccine coverage. As long as there is measles somewhere in the world, it will be exported by travel and immigration. What happens next depends on vaccine coverage. If coverage rates are low, sustained spread of measles takes place. With high coverage herd immunity occurs, and imported cases lead only to outbreaks (of varying size) among those who are not vaccinated. Usually they are small and self limiting; but if sizable pockets of unvaccinated people exist the outbreaks can be large.

    I always felt superior to my British friends and expressed disbelief at the furore in the United Kingdom about possible adverse effects of the measles, mumps, and rubella vaccine, leading to protests, a falling rate of vaccination, and increasingly larger outbreaks. Didn’t they get it, I wondered? The threat of endemic measles in a population surely outweighs the disproved or unproved threats of problems caused by vaccine preservatives or the vaccine itself. Something like this would never happen in the US.

    But it has. I read with great disappointment the recent Centers for Disease Control and Prevention (CDC) bulletin reporting that the number of measles cases was at a 10 year high in the US in the first half of 2008 (Morbidity and Mortality Weekly Report 2008;57;893-6). It turns out that this spike was not due to an increase in imported cases. Rather, it was attributable to larger numbers of unvaccinated children of school age. The parents of most of them had requested exemptions to school vaccination requirements or had educated their children at home and thus dodged vaccination requirements. The CDC is concerned that the outbreaks may herald a new wave of measles cases around the country.

    Although the number of cases—131—is relatively small, they are crucially important. Some children will always be unvaccinated and vulnerable—all those less than 1 year of age and the small number of older children who are immunologically compromised. They rely on herd immunity for protection. The CDC bulletin says that when the vaccination rate dips below 90% in preschool children and below 95% in school age children herd immunity is no longer as effective, outbreaks get larger, and sustained spread becomes possible.

    Almost two thirds of the unvaccinated children who got measles in the US had not been vaccinated because of their parents’ beliefs. And most of these parents were thought to have concerns that the MMR vaccine would cause adverse effects such as autism in their children.

    What’s going on here? Aren’t doctors making it clear to parents what a mistake it is not to vaccinate their children? I don’t think that is the problem. Doctors I have spoken to blame much of the parental concern on sensationalist media coverage and the internet. All you need to do is enter “vaccines and autism” in a search engine to get an eyeful of teary anecdotes and “scientific” correlations claiming to prove the association between jabs and disease.

    Surely the declining authority of doctors and the increasing impersonality of medical care—and resulting lack of trust—have a role as well. Many people I know are forced to change doctors annually as their health insurance coverage changes. This hinders continuity of care and the growth of a trusting relationship.

    And parents may also be rebelling against the seemingly endless number of childhood vaccines that are now recommended. With the addition of rotavirus and pneumococcal vaccines and the return of injections for polio vaccine, it is no surprise that parents express concern that their children are being turned into pin cushions. If children get shots every month or two from birth to age 18 months, there are plenty of chances to correlate any problems that occur with a recent immunisation. And if you search hard enough you can no doubt find that someone somewhere has correlated your child’s symptoms—behavioural, neurological, whatever—with a shot that your child has just had.

    It’s discouraging that real, measurable achievements in public health are in danger of being reversed. I don’t have any brilliant suggestions of how to reverse this trend. Government agencies and medical professional societies are doing their best to educate the public about the importance and safety of vaccines. My internet search brought up many responsible discussions of vaccine safety along with the sob stories and wacko science. But just as “on the web no one knows you are a dog,” it is also true that on the web many will not know you are a charlatan or a well meaning naïf.


    Cite this as: BMJ 2008;337:a1517

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