Thread by @MonicaGandhi9

Think we are getting tripped up on definition of #herdimmunity: form of indirect protection from an infection that occurs when a significant % of population has become immune to an infection (through vax or previous infection). 74 cases/9.05 million Israel
ourworldindata.org/coronavirus/co…

(with openings and mingling) with a 63% 1st dose vaccination rate >16 years old (Pfizer only approved down to 16) means those unvaccinated (not yet or children) have INDIRECT protection from infection because virus not circulating much
ourworldindata.org/covid-vaccinat…

This is why children back in school without masks/ distancing: they are not protected by vax but by levels of virus circulating to be so low it is close to 2019. Do you see what I mean by definitions? Call it containment but protects others for more & more adults to be immune

So let's go back to my picture of herd immunity: more and more of us adults are getting pink, protecting the white sheep. I am wondering if we are confusing herd immunity with ERADICATION which we have done for only one virus (smallpox). I like Biden's 70% 1st dose metric >18 yrs

And of course, immunity means a combination of natural infection + vaccination - that is in the textbook definition of herd immunity. We wanted to get there mainly through vaccination but of course places like CA had high surges (we were hit hard in winter)

To this point, as @JenniferNuzzo points out, since US started vaccinating oldest first, % of all cases in younger groups increased 1st prior to tipping point. Now cases in adults AND kids decreasing. Vaccinating adults (of the herd) protects children:
downloads.aap.org/AAP/PDF/AAP%20…

Remember, #herdimmunity is form of indirect protection from an infection that occurs when significant % of population becomes immune (through vaccine or natural infection); unvaccinated (children in this case) protected by low cases; don't confuse with eradication please

Indeed, only virus that has been eradicated is smallpox. I have heard people say we must eradicate every #covid19 virus from face of earth but low cases will keep unvaccinated protected if we get herd immunity & at some point, countries with high vax must turn to other diseases.