The FDA’s Vaccines and Related Biological Products Advisory Committee unanimously agreed to recommend a booster dose of Janssen Biotech Inc.’s COVID-19 vaccine for those age 18 years and older at least two months following the first dose. In the end, the vote swung on numbers from Janssen showing a booster significantly improved efficacy among study participants. Janssen’s data leaped to 94% protection after a booster dose, up from 70% efficacy following the first dose. That higher efficacy rate nearly matches that of the mRNA vaccines from Moderna Inc. and Pfizer Inc.-Biontech SE.