Top vaccine developers are upgrading COVID-19 shots as mutations threaten our progress in curbing the pandemic

• The emergence of coronavirus variants threatens to lower the efficacy of COVID-19 vaccines and extend the pandemic’s trajectory.
• A barrage of data released in January showed a variant widely circulating in South Africa is particularly troubling.
• Experts told Insider that vaccines still work against these variants, even if the effectiveness is slightly lower than against the original strain.

A troubling strain of the coronavirus has emerged, first in South Africa. It’s now spreading around the world, including in the US.

Potentially more troubling: A flurry of data released this week shows the virus has changed in ways that likely diminish the efficacy of leading vaccines.

“We can see that we are going to be challenged,” Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, said Friday, calling the most recent findings “a wake-up call for us to be nimble and to be able to adjust.”