3 ms·
Smallpox? Polio? Ebola? None of these ended with "herd immunity" Before vaccination measles epidemics happened every few years, killing over 2 million people e
by DanBC 6y ago
Smallpox? Polio? Ebola? None of these ended with "herd immunity"
Before vaccination measles epidemics happened every few years, killing over 2 million people each year. https://www.who.int/news-room/fact-sheets/detail/measles https://www.who.int/news-room/fact-sheets/detail/measles
> Before the introduction of measles vaccine in 1963 and widespread vaccination, major epidemics occurred approximately every 2–3 years and measles caused an estimated 2.6 million deaths each year.
Where's the herd immunity to measles?
- ceejayoz 6y agoHerd immunity doesn't necessarily mean "fully prevents outbreaks". https://en.wikipedia.org/wiki/Herd_immunity#History https://en.wikipedia.org/wiki/Herd_immunity#History > Herd immunity was first recognized as a naturally occurring phenomenon in the 1930s when A. W. Hedrich published research on the epidemiology of measles in Baltimore, and took notice that after many children had become immune to measles, the number of new infections temporarily decreased, including among susceptible children. (Measles is also fairly uniquely virulent. https://en.wikipedia.org/wiki/Basic_reproduction_number https://en.wikipedia.org/wiki/Basic_reproduction_number)