A surge in Covid-19 hospital admissions driven by the BA.5 subvariant of Omicron, accompanied by the inability of vaccines to prevent reinfection, has prompted health policymakers to rethink their approach to boosters.
US regulators last week recommended changing the design of vaccines to produce a new booster targeting Omicron — the first change to the make-up of shots since their introduction in late 2020. Research into immune imprinting