I appreciate the focus of political science professor John Kirlin on knowledge-driven policy. As a professor of microbiology and immunology, I would like to clarify how current knowledge of vaccination informs current policy and the important pending legislation Senate Bill 277 (“‘Precision medicine’ should help inform vaccine policy”; Viewpoints, May 17).
First, it should be noted that there remains very little uncertainty regarding the safety and effectiveness of the vaccines mandated for California schoolchildren. Rigorous epidemiological research and safety monitoring shows that the currently recommended combination of vaccines is safe and highly beneficial for the vast majority of individuals.
Kirlin’s call for increased support for research to improve the application of precision medicine principles to better predict the benefits and risks of vaccination for individuals is timely and would certainly be welcomed by the scientific community. The current medical exemption policy already protects children who are known to have weakened immune systems due to illness or medical treatments, as well as those who have had severe allergic reactions or adverse events after vaccination in the past.
Continued research may uncover improved methods to better predict which individuals will fail to mount effective vaccine responses that provide protection from infection, and the rare individuals who will have serious adverse reactions, before they happen.
It is also important to acknowledge that no vaccine policy will be effective if vaccines are provided only to a limited number of individuals. In the face of uncertainty, the cautious policy is to require vaccination unless there is clear evidence that a medical exemption is needed. The serious “adverse events” caused by the infections that are prevented by mass vaccination are far more frequent than the adverse effects of the vaccines themselves. Moreover, diseases such as measles and whooping cough spread readily through populations with even relatively small numbers of unvaccinated individuals, not sparing vulnerable children with weakened immune systems who cannot protect themselves by vaccination.
In the future, personalized medicine approaches may improve the application of medical exemptions to vaccination. In the present, the societal imperative to protect California children from infectious diseases must trump fear about the slim uncertainties that remain regarding vaccine safety. That is why I support SB 277.
K. Mark Ansel is an associate professor in the Department of Microbiology & Immunology at the University of California, San Francisco.