STAT reports:

The question about how Covid-19 vaccines stand up to coronavirus variants often gets distilled to: Do they work?

The simplest answer is yes. People who’ve received one of the highly powerful vaccines don’t need to be too worried about the variants for now, experts say.

But the complete answer is more complicated.

The real question isn’t whether the vaccines work, but how well they do. Even the best vaccines allow some “breakthrough infections” — infections in people who’ve been immunized. And there are outstanding questions about how the continued emergence of variants — such as the one that’s popped up in India and appears to be helping fuel the explosion in cases there — will shape the Covid-19 pandemic into the future and potentially affect vaccine strategies.

It’s also helpful to specify what you’re talking about. Different countries are deploying different vaccines, and different variants have different tricks up their genetic codes. Clinical trials generally measured how well the vaccines prevented symptomatic Covid-19, but just as relevant are such questions as, how well do the vaccines protect against severe disease, hospitalization, and death? Do they block infections entirely, even those without symptoms? And even if people still contract the virus, does being immunized make them less infectious?

“There’s no simple, one-line sound bite,” said John Moore, a professor of microbiology and immunology at Weill Cornell Medical College.

Below, STAT outlines the latest on some of the vaccines’ performance against the variants, what’s known about the variant of concern in India, and how the continued emergence of variants will shape the future of Covid-19. [Continue reading…]