FDA advisers recommend updating COVID vaccines to target omicron strain.

The FDA's scientific advisers have recommended that the next round of COVID-19 shots in the US should only include protection against the newest variants, specifically the XBB branch of the omicron family tree. Vaccine makers have said they could have updated vaccines available within months, depending on the strain. The FDA will make the final decision. The current vaccines still contain the original coronavirus strain, which was long ago supplanted by mutated versions as the virus rapidly evolves. The hope is that the XBB variants are different enough to spark the immune system to make more diverse, cross-protective virus-fighting antibodies.