The study from South Africa suggested that two doses of the AstraZeneca vaccine provided „substantially reduced“ protection against mild to moderate Covid-19 disease from the new virus variant first identified there, known as B.1.351.

The study has not yet been peer reviewed or published in full, so many unknowns remain. What we do know is that it included a relatively small number of volunteers who were predominantly young and healthy and therefore not likely to suffer from severe Covid-19 disease.