From Alan Bundy, Edinburgh, UK
What are we to make of the small study in South Africa that found the Oxford/AstraZeneca covid-19 vaccine doesn’t prevent mild or moderate illness from the B.1.351 variant found there? The South African health minister’s decision, on 7 February, to put the vaccine’s roll-out in the country on hold seems to be based on the assumption that it isn’t very effective for this variant (13 February, p 7).
It seems unlikely, however, that the vaccine would only prevent severe infection. A more likely explanation is that it reduces the severity of nearly all cases, so that people who might otherwise have had a severe illness only get a moderate one and that people who might otherwise have had a moderate illness get a mild one. If so, then the sooner the vaccine is rolled out there, the better.
