HotAir hotair.com 16 Jul, 2021 04:15 am

Does the Delta variant mean herd immunity is now impossible? – HotAir

Does the Delta variant mean herd immunity is now impossible? – HotAir

A basic rule of epidemiology is that the more contagious a virus is, the greater the share of the population that has to be immunized from it in order to achieve herd immunity.Initially we were told that immunizing 60-70 of the population from SARS-CoV-2 might be expected to provide herd immunity.Which means the target for herd immunity has risen.2/ — Adam Kucharski (@AdamJKucharski) July 15, 2021 If herd immunity through vaccination alone not possible, need to either: A) keep some control measures in place indefinitely, B) prepare for exit wave as measures relaxed, C) update what are already very good vaccines to be even more effective.

Even if you assume that 80 percent of the adult population already has immunity of one sort or the other, Kucharski’s math suggests we still have around 50 million adults in harm’s way before we can expect herd immunity.4/ — Adam Kucharski (@AdamJKucharski) July 15, 2021 An “exit wave” is a wave in which pretty much everyone who hasn’t already gained immunity through vaccination or previous infection ends up being infected.

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