Some signs AstraZeneca vaccine durability could be a year: Chief investigator

LONDON: Scientists testing the efficacy of AstraZeneca's experimental Covid-19 vaccine said they cannot be sure if the virus will mutate in a way that would make it necessary to repeat vaccination every year, but that for now that looks unlikely.

"We don't know yet if this virus will be mutating away from the immune response," the Oxford vaccine group's director Andrew Pollard told reporters at a briefing, adding: "There is no evidence of that yet."

Asked whether the vaccine - which showed at least 70% efficacy in interim data from phase III trials - would be likely to give longer-term protection, Pollard said: "We've got optimism about immune response lasting at least a year," but that trials needed more time to be able to give any confirmation of durability.