CDC shifts pandemic goals away from reaching herd immunity
Vaccines have been quite effective at preventing cases of COVID-19 that lead to severe illness and death, but none has proved reliable at blocking transmission of the virus, Jones noted. Recent evidence has also made clear that the immunity provided by vaccines can wane in a matter of months.
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The CDC’s new approach will reflect this uncertainty. Instead of specifying a vaccination target that promises an end to the pandemic, public health officials hope to redefine success in terms of new infections and deaths — and they’ll surmise that herd immunity has been achieved when both remain low for a sustained period.