Part 3: Vaccination in LA

Vaccination policy has varied widely since their inception in the 1950s. In the first years, perhaps helped by folks with vivid memories of the horrors vaccination promised to erase, compliance was unquestioned and practically universal. The benefits were so obvious - what sane parent wouldn't want their child free of debilitating and potential fatal diseases?

Since then things have definitely changed. Polio, rubella, measles, mumps, smallpox, and their like are spoken of in the past tense. The near 100% compliance with vaccination programs have eradicated many of these diseases by rendering it impossible for these contagious diseases to find susceptible individuals and spread throughout society. The average child born in the United States faces practically zero risk from these killers of the past. Paradoxically, as vaccines have vastly reduced the actual risk of contracting a fatal contagious disease, the perceived risk posed by the vaccines themselves has risen comparatively. As the memory of these diseases fade and become inconsequential, the risk of health hazards that are incurred with the use of vaccines rise in comparison. This may explain the relatively recent rise in the numbers of children being exempted from vaccination.

While the right to choice and free expression of will are quintessential American qualities that should not be sacrificed, vaccination is a special intersection of personal choice with greater good. Vaccination as a concept works only when a great majority of the population is vaccinated. In diseases that are transmitted between individuals, vaccination acts to break the chain of infection and spread. An infected Person A cannot infect an immunized Person B, thereby limiting the range of an outbreak. As a side effect, widespread vaccination can also protect a small group of unvaccinated individuals as well, since it is likely that a disease outbreak will not reach the unvaccinated population due to the great number of vaccinated individuals in the general population. This is called "herd immunity," and the likely rationale behind allowing a limited number of exemptions from mandatory vaccination. However, should the population of unvaccinated individuals exceed a critical fraction of the population disease outbreaks become more likely, spreading from vaccinated carriers of the disease to unvaccinated individuals or between unvaccinated individuals themselves. There is even a chance that unvaccinated individuals can even pose a threat to those who have been vaccinated, since no vaccine is 100% effective and relies on mass vaccination to provide a secure barrier against disease outbreaks.

California is home to a diverse population, representing a wide range of personal beliefs and backgrounds that manifest as great heterogeneity with regards to behavior. At present approximately 1.5% of children are unvaccinated against at least one of the standard vaccinations, ranging from 10-19% in some areas. California has been home to several recent high-profile outbreaks of commonly controlled diseases, such as a measles outbreak in February 2008 that affected 12 children, 9 of whom had not been innoculated against measles (3 were too young to have received the vaccine). Not only are the unvaccinated at greater risk to contract disease, there is also evidence that unvaccinated individuals can also infect vaccinated individuals. A  2006 study in Iowa showed that of 219 individuals who had contracted mumps, the majority had received vaccination against it.

As vaccination cannot protect against all strains of a disease and also has varying rates of efficacy depending on the individual, the greatest public health benefit of widespread vaccination is the establishment of herd immunity that reduces the chance for an individual to be exposed to a disease. Should the the number of unvaccinated rise to beyond a tiny minority, the health of the majority is jeopardized.

Los Angeles is the proud home to a great diversity of beliefs and opinions that inform our actions in myriad ways. However, tolerance of the individual has to be tempered with respect for the greater good. Common reservations about vaccines appear to be unfounded and unsupported by reputable scientific research. While reservations about reactions to vaccines and concerns about their scheduling are valid and should be seriously considered and challenged by concerned parents, it appears essential that vaccination remain a widespread practice to prevent the return of the diseases that many have worked so hard to eradicate.

References:

"Public Health Risk Seen as Parents Reject Vaccines." http://www.nytimes.com/2008/03/21/us/21vaccine.html

"Herd Immunity." http://en.wikipedia.org/wiki/Herd_immunity