The scattered stories from across the nation can play like a merciless irony: Somebody exams constructive for the coronavirus despite the fact that they’ve already obtained one or each doses of a Covid-19 vaccine.
It’s occurred to at the very least three members of Congress not too long ago:
How can that occur?
Specialists say circumstances like these will not be shocking and don’t point out that there was one thing unsuitable with the vaccines or how they had been administered. Right here is why.
Vaccines don’t work immediately. It takes just a few weeks for the physique to construct up immunity after receiving a dose. And the vaccines now in use within the U.S., from Pfizer-BioNTech and Moderna, each require a second shot just a few weeks after the primary to succeed in full effectiveness.
Nor do they work retroactively. You’ll be able to already be contaminated and never comprehend it while you get the vaccine — even if you happen to not too long ago examined unfavorable. That an infection can proceed to develop after you get the shot however earlier than its safety totally takes maintain, after which present up in a constructive check outcome.
The vaccines forestall sickness, however possibly not an infection. Covid vaccines are being licensed based mostly on how nicely they preserve you from getting sick, needing hospitalization and dying. Scientists don’t know but how efficient the vaccines are at stopping the coronavirus from infecting you to start with, or at retaining you from passing it on to others. (That’s why vaccinated people should keep wearing masks and sustaining social distance.)
Even the very best vaccines aren’t good. The efficacy charges for Pfizer-BioNTech and Moderna vaccines are extraordinarily excessive, however they don’t seem to be 100%. With the virus nonetheless spreading uncontrolled within the U.S., among the hundreds of thousands of not too long ago vaccinated individuals had been sure to get contaminated in any case.