The scattered reviews from across the nation can play like a merciless irony: Somebody exams constructive for the coronavirus despite the fact that they’ve already acquired one or each doses of a Covid-19 vaccine.
It’s occurred to at the very least three members of Congress just lately:
How can that occur?
Consultants say instances like these should not stunning and don’t point out that there was one thing unsuitable with the vaccines or how they have been administered. Right here is why.
Vaccines don’t work immediately. It takes a number of 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 a number of weeks after the primary to achieve full effectiveness.
Nor do they work retroactively. You may already be contaminated and never understand it once you get the vaccine — even when you just lately examined unfavorable. That an infection can proceed to develop after you get the shot however earlier than its safety absolutely takes maintain, after which present up in a constructive take a look at consequence.
The vaccines forestall sickness, however perhaps not an infection. Covid vaccines are being licensed primarily based on how properly they hold 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 preserving you from passing it on to others. (That’s why vaccinated folks ought to hold carrying masks and sustaining social distance.)
Even the perfect vaccines aren’t good. The efficacy charges for Pfizer-BioNTech and Moderna vaccines are extraordinarily excessive, however they aren’t one hundred pc. With the virus nonetheless spreading uncontrolled within the U.S., a number of the thousands and thousands of just lately vaccinated folks have been sure to get contaminated in any case.