A protein-based COVID-19 vaccine made by Sinopharm, when given as a booster after two doses of an earlier shot from the Chinese firm, elicited a stronger antibody response against the Omicron variant than a third dose of the original, a study showed. The study, which was published on Tuesday and had not been peer-reviewed, came amid concerns over the effectiveness of Sinopharm’s BBIBP-CorV shot, one of the two leading COVID-19 vaccines exported by China, against the Omicron variant. An earlier study showed a BBIBP-CorV booster had weaker neutralization against Omicron than against an older coronavirus strain from the central […]