The Herd Immunity Paradox

Herd immunity is an extremely important concept. The basis for herd immunity is all around us, with more than 91.9% of children receiving the MMR vaccination. The CDC reports, “Before the measles vaccination program started in 1963, an estimated 3 to 4 million people got measles each year in the United States… Since then, widespread use of measles vaccine has led to a greater than 99% reduction in measles cases compared with the pre-vaccine era” (Measles 2016). Even though just over 90% of the population received the MMR vaccine at a very young age, measles is all but eradicated in the United States. However, the question stands: Should we really be teaching herd immunity to the public?

A superficial study would reveal that yes, herd immunity is at work and is very important to the health of the public. However, a deeper look reveals something quite different. The idea of herd immunity relies on the public being educated enough to draw the correct conclusions. Those who fail to draw these conclusions, however, tend to take the “Well if everyone else’s children are vaccinated then I don’t need to vaccinate my children” idea and run with it. The problem is not that the concept of herd immunity is wrong, it is that a lot of people in the public are wrong.

“The unvaccinated person is protected by the bodies around her, bodies through which disease is not circulating. But a vaccinated person surrounded by bodies that host disease is left vulnerable to vaccine failure or fading immunity” (Biss 2015). When phrased like this, it appears as though vaccinated people get the short end of the stick. Not only are they charged with protecting those not educated enough to protect themselves, but they are also putting themselves in danger if their immunization fails them. The paradox comes into play when their immunization does fail them, and they then spread the disease to those who were not vaccinated against it, who in turn spread it to others whose immunity has already been weakened.

The idea of Generalized herd effects also plays a role in this issue. Generalized herd effects are “vaccine-derived effects that alter the epidemiology of non-vaccine-targeted pathogens across the population at large, including those who did not vaccinate” (Mina 2017). For instance, if a portion of the population is vaccinated for a disease that does not display the benefits of herd immunity, such as influenza, the effects of the vaccine on post-influenza conditions (severe bacterial infections are very common among post-flu individuals) will spread to the unvaccinated populations, as they are the ones who most often contract the flu. This shows that herd immunity is not a fail-safe for all diseases, and that an increased immunity among a part of the population may cause more harm to the unvaccinated than good.

So, if teaching herd immunity to the masses is failing, then how can we educate those who still can not understand? As Biss suggests in On Immunity, perhaps teaching “hive immunity” is the way to go. Hive immunity states that “The health of any individual bee…depends on the health of the hive…The cooperative work of the bees…is an example of the kind of collective problem solving our own society depends on,” (Biss 2015). Teaching hive immunity may solve the problem of those in the herd who fail to recognize the validity of vaccinations.

Biss, Eula. On Immunity: an Innoculation. Fitzcarraldo, 2015.

“Measles (Rubeola).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 22 Nov. 2016, www.cdc.gov/measles/vaccination.html.

Mina, Michael J. “Generalized herd effects and vaccine evaluation: impact of live influenza vaccine on off-Target bacterial colonisation.” Journal of Infection, vol. 74, 23 June 2017, p. S104., doi:10.1016/s0163-4453(17)30199-8.