Does herd immunity matter?

In a video posted on Twitter, ACIP committee member Robert Malone claims that vaccines aren’t very effective and that warnings about unvaccinated kids endangering others are just scare tactics.

Vaccines work. They are not 100% effective, but for many, vaccines protect against disease, hospitalization, and death. Because vaccines don’t work 100% of the time, some people will be vulnerable to a disease even though they have been vaccinated. Also, some people cannot be vaccinated because they are too young or immunocompromised, so they are vulnerable, too. Those people are at risk of get sick or worse from a disease, so if others in their community are unvaccinated and therefore susceptible to contracting and passing along a disease, those people pose a risk to those who aren’t protected by their own vaccines.

Herd immunity, or community immunity, happens when enough people in a community are immune to a disease that they “shield” those who don’t have immunity from getting the disease. What constitutes “enough” is dependent on how contagious a specific disease is. If not enough people in a community are vaccinated and the threshold to reach herd immunity is not met, then anyone who is susceptible to the disease, whether unvaccinated for personal or medical reasons, or for those for whom the vaccine didn’t work, is at risk from the disease.

Studies show that when vaccination rates drop, diseases return. For example, measles outbreaks tend to happen in areas with low vaccination rates. Then even the vaccinated are at increased risk of getting sick or worse.