LONDON - Vaccine developer Novavax announced on Thursday that its vaccine offers high levels of protection against the original coronavirus strain that causes COVID-19, but the vaccine’s efficacy is diminished by some coronavirus variants, including one that originated in South Africa.Novavax announced on Twitter that its vaccine has 96% efficacy against the original strain of the coronavirus, according to a recent U.K.
trial. But the company said its vaccine is only 55.4% effective against the B.1.351 strain, first detected in South Africa in December.