Vaccines and Outbreaks

The story of vaccination is a fascinating one. Vaccines are often hailed as a true game-changing medical breakthrough. I've never met someone with polio who was born after 1950. The eradication of smallpox is something medical students today never appreciate. The idea that the immune system can be primed with killed or attenuated virus is a beautiful one that has borne out in practice. Yet in the last decade or so, the gains made by vaccinations have slowly withered away. With increasing unfounded fear over side effects such as autism, public stances made by celebrities, and the prevalence of unproven information on the internet, parents are starting to choose not to vaccinate their children. This blog isn't meant to be a soapbox and I don't want to give medical advice, but this trend is disturbing to me. My interpretation of the information out there is that vaccines do not cause autism or have detrimental long-term side effects. They do, however, protect children from diseases. Furthermore, vaccines have a property called herd immunity, the idea that a large population of vaccinated individuals will protect those who are not vaccinated.

This change in our society and culture to decline vaccination is scary because of outbreaks that occur in communities with a high prevalence of unvaccinated children. In 2010, there were 9000 cases of pertussis with 10 deaths in California and these cases clustered in communities with high rates of vaccine declination (measured by exemptions for kids to attend kindergarten without proper vaccines). The outbreaks and the unvaccinated children also clustered in communities with high socioeconomic status. As the outbreaks show, when fewer people are vaccinated, herd immunity is lost, and diseases that are entirely preventable can even cause death.