Terrific Op-Ed Regarding Vaccine Safety and Herd Immunity

Dr. Bob wrote a really good op-ed in the Daily News Sun this week.  I thought I’d include it in this week’s Policy Update because it’s so well written.

I’d like to try to offer some perspective in response to Diane Douglas’ May 24 commentary on vaccine safety.

“Herd immunity” is a medical miracle, preventing millions of cases of disease and many deaths every single year.  Yet it’s a pretty simple concept. 

No vaccine works perfectly.  But the more people are immunized, the less likely one person’s germs are to spread to the next person.  Depending on the disease, one sick person might infect several others, each of whom infect several more.  That’s an outbreak.  But if you keep the level of immunizations high enough that there is less than one new case of disease for each original sick person, then outbreaks simply don’t happen.  Your personal immunity from your own vaccine never gets put to the test, because you are never exposed in the first place.  This makes vaccines unlike any other health decision – because your action affects others.

Herd immunity results in remarkable protection.  Diseases that were once nearly universal can be practically wiped out.  In the example of smallpox, a disease that killed perhaps half a billion people in the 20th century alone, we were able to eliminate the disease entirely.  There’s no biological reason that we couldn’t do the same with some other diseases – we’ve come close to eliminating polio, for example.

You are, right now, being protected not just from the vaccines you got, but from all the vaccines that everyone around you got.  And what you do by immunizing yourself or your kids doesn’t just benefit your own family – it helps to protect everyone else, notably all those who, for medical reasons, can’t be vaccinated themselves.  Similarly, choosing not to be vaccinated, yet living among others, lowers that level of herd immunity and puts others at risk.  Exactly what that threshold of herd immunity is varies by disease (how infectious it is), by the vaccine (how effective it is), and by the setting (how congested and interactive people are).  Among the worst settings for spreading disease are schools and childcare centers. 

That concept of pitching in to benefit each other is a thoroughly American idea, from the early colonists creating a commons in nearly every town, to compulsory quarantine in the 1600s, to requiring vaccination for school attendance beginning in 1855, to early and repeated court decisions that have upheld various vaccination laws and regulations since at least 1905.  This is not new, and since it has been in place for all our entire lives, it is obviously not a “slippery slope” that has led to any sort of draconian consequences.

Vaccines must meet the same safety and efficacy standards that other pharmaceutical products must reach before being licensed for use in the U.S.  The benefits to an individual and to society of vaccines far outweighs the small risk, for example, of an allergic reaction.  Yet recognizing the societal value of immunizations, the nation established the National Vaccine Injury Compensation Program, which requires a far lower burden of proof and a simpler process than a lawsuit, to assure that anyone who legitimately might have been harmed by vaccines is compensated.  Even with these looser standards, which mean that some people are compensated even though it may be unlikely that the vaccine caused the injury, approximately one person is compensated for every 1 million doses of vaccine given in this country.

In her commentary, Ms. Douglas invoked appeals to individual liberty.  All of us can relate to that.  America guarantees many liberties, but we establish limits when others might be harmed.  Any one of us is free to use public streets, but we don’t get to drive however fast we want, because that would put others at risk.  Similarly, any one of us is free to send our kids to public schools, but we should not be allowed to deliberately put other people’s children at risk by ignoring vaccine requirements. 

Bob England, MD, MPH

Former Director (2006-2018) of the Maricopa County Department of Public Health