Scientists try to keep up with faster coronavirus evolution

The rapid evolution of the coronavirus into an alphabet soup of subvariants presents a vexing challenge to health officials: They must make far-reaching policy decisions based on little biological certainty of which viral variants will be dominant this fall or winter.

The Food and Drug Administration said at the end of June that it would update virus vaccines for a booster campaign in the fall targeting highly contagious omicron subvariants. But the ground is shifting beneath its feet.

In just eight weeks, the subvariant known as BA.5 has gone from a blip in U.S. case counts to the dominant version of the virus, now making up more than three-quarters of new cases. Perhaps the most transmissible subvariant yet, it is pushing up positive tests, hospitalizations and intensive care admissions across the country,

There is no evidence that BA.5 causes more severe disease, but the latest metrics certainly bust the myth that the virus will become milder as it evolves.

Wednesday, July 20, 2022 - 11:35am