...the AstraZeneca-Oxford coronavirus vaccine...did not protect...from mild or moderate illness caused by the [South African] virus variant.
The findings were a devastating blow to the country’s efforts to combat the pandemic.
Scientists in South Africa said on Sunday that a similar problem held among people who had been infected by earlier versions of the coronavirus: the immunity they acquired naturally did not appear to protect them from mild or moderate cases when reinfected by the variant, known as B.1.351.
The developments, coming nearly a week after a million doses of the AstraZeneca-Oxford vaccine arrived in South Africa, were an enormous setback for the country... And they were another sign of the dangers posed by new mutations in the coronavirus. The B.1.351 variant has already spread to at least 32 countries, including the United States.
... the fact that it showed minimal efficacy in preventing mild and moderate cases of the new variant added to the mounting evidence that B.1.351 makes current vaccines less effective.
Pfizer and Moderna have both said that preliminary laboratory studies indicate that their vaccines, while still protective, are less effective against B.1.351. Novavax and Johnson & Johnson...both reported lower efficacy [against the South African variant].
There was virtually no difference in the numbers of people in the [Astro-Zeneca] vaccine and placebo groups who were infected with B.1.351, suggesting that the vaccine did little to protect against the new variant.
