A: NOPE
In a news story picked up by many media outlets yesterday, headlines regarding the duration of immunity were inferred from recent CDC guidance on quarantine.
The relevant sentence from the CDC was:
“People who have tested positive for COVID-19 do not need to quarantine or get tested again for up to 3 months as long as they do not develop symptoms again.”
These guidelines were likely meant to lessen the burden of quarantine for people already infected and in fact mean that….
People are protected for *at least* three months, not *up to* three months.
As Prof. Carl Bergstrom clarified on twitter:
“There is nothing at all in the CDC statement about evidence that immunity wanes after three months. Rather, they are making a recommendation based on positive evidence that immunity doesn’t wane before three months.”
So chalk this up to bad headlines– what we currently know is that infection *likely* provides some protection but we don’t yet know for how long. But there is no evidence for immunity only having a 3 month duration.
