What’s next for COVID-19 vaccines? Update, 27 January, 2:30 p.m.: On 26 January, an FDA advisory panel voted unanimously to harmonize the makeup of all COVID-19 vaccines. In the future, the primary two-dose series—currently based on the SARS-CoV-2 strain that emerged in Wuhan, China—and booster shots, currently bivalent, will be based on the same virus variants. The panel also broadly agreed with FDA's proposal to shift to annual, fall COVID-19 boosters for most of the U.S. population.