Just weeks into the rollout of vaccines to combat COVID-19, researchers are shifting their focus to a new class of potential shots to take on the threat posed by fast-spreading mutations.
Dangerous coronavirus variants first identified in Africa, Europe and South America are carpeting the globe, pushing scientists in the U.K. and elsewhere to target multiple versions of the pathogen in a single shot and perhaps head off more lethal foes that may emerge.
A variant that arose in South Africa has already shown itself capable of partially evading defenses raised by several vaccines. The country paused rolling out a shot from AstraZeneca PLC because it offered minimal protection against mild to moderate illness cause by the mutant, called B.1.351. With a spreading virus comes an increased risk of more alarming mutations.