LONDON, Nov 23 (Reuters) - 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 on 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.
(Reporting by Kate Kelland and Kate Holton, Editing by
Catherine Evans)