> the only people at risk are those that have not been vaccinated Remember that this set includes people that cannot receive the vaccine because of e.g autoimm

> the only people at risk are those that have not been vaccinated Remember that this set includes people that cannot receive the vaccine because of e.g autoimmune disorders, serious allergic reactions, etc. These people need the herd immunity to keep the general risk of infection low. As long as the number of anti-vaxxers is very small, they similarly benefit from the herd immunity as "free riders". Once the number of free riders crosses a threshold[1], non-linear effects can rapidly amplify the spread of the disease among the population. Preventing any disease from gaining a "critical mass" in the population is an important part of how they work. > Fortunately the anti-vaxxers are a small minority Unfortunately that isn't really true in some areas.[2] > so the consequences for society as a whole are manageable. That management has already started to fail in CA (and other areas), where the rapid decrease in vaccination rates cause measles and whooping cough outbreaks[3]. [1] https://en.wikipedia.org/wiki/Herd_immunity#Mechanism https://en.wikipedia.org/wiki/Herd_immunity#Mechanism [2] https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6341a1.htm?s_cid=mm6341a1_w https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6341a1.htm?s_cid... [3] https://www.advisory.com/daily-briefing/2014/09/30/in-wealthy-la-schools-up-to-of-parents-exempt-kids-from-vaccines https://www.advisory.com/daily-briefing/2014/09/30/in-wealth...