Newer subvariants, related to the BA.4 and BA.5 omicron subvariants, are making up an increasing number of COVID cases in the U.S., but experts say not to panic.
Newer subvariants, related to the BA.4 and BA.5 omicron subvariants, are making up an increasing number of COVID cases in the U.S., but experts say not to panic.