Pfizer said it expects that a Covid-19 vaccine could, like the flu shot, be an inoculation that is needed regularly to be effective.“There is a likely scenario that either the vaccine’s immunity will not be lasting forever," said Chief Executive Officer Albert Bourla in an interview Tuesday, “or that the virus will mutate, or that the virus will find ways to come back again and again."The drugmaker expects to bring the vaccine to market in two phases.
The first is a so-called pandemic phase, which Pfizer expects to last through 2020 or into 2021, Bourla said. During that period, Pfizer will aim to deliver a safe, effective and affordable vaccine for governments around the world.Last week, the U.S.