RIO DE JANEIRO, BRAZIL - Covid-19 vaccine developers are increasingly asserting that the world will need annual booster vaccines, or new vaccines against coronavirus variants of concern, but some scientists are questioning when, or if, such vaccines will be needed.
More than a dozen influential infectious disease and vaccine development experts said that there are growing indications that a first round of global vaccinations could offer lasting protection against the coronavirus and the variants of most concern discovered so far.
Some of these scientists expressed concern that public expectations regarding booster vaccines against Covid-19 are being created by pharmaceutical . . .