Future COVID-19 booster shots will likely need fresh formulations as new coronavirus variants of concern continue to emerge

PROMO Health - Vaccine Words Blocks - iStock - Aksana Kavaleuskaya

Being up to date on COVID-19 vaccines means having had three or four doses of the same shot at this point. Current boosters are the same formulations as the first authorized shots, based on the original strain of the coronavirus that emerged in late 2019.