COVID-19 vaccine less effective in South Africa

A prominent scientist has expressed deep concern that a new vaccine only worked on half of those patients who received it in a trial in South Africa.

The Novavax vaccine had nearly 90% success rate in the UK, but only 49,4% efficacy in a smaller test in South Africa.

Prof Salim Abdool Karim, who heads South Africa's coronavirus advisory panel, warned some countries could get left behind in terms of the vaccine roll-out.

The virus in South Africa has mutated in a way that appears to make it significantly more resistant to some current vaccines.

In the latest trial, the Novavax vaccine proved effective in only 49,4% of cases overall. (It was 60% effective among those without HIV — but more than 20% of South Africans are HIV-positive.)

Although some scientists here have praised these figures, Prof Karim said the success rate was "deeply concerning".

Vaccines can and will be tweaked to make them more effective against mutations of Covid-19. But Prof Karim the most authoritative voice on the pandemic in South Africa warned that more mutations were inevitable, and the scientific community needed to work harder to get ahead of the virus.

There are already concerns that poorer countries will not get vaccines fast enough.

Prof Karim said there was now an additional risk that richer nations would be able to achieve some level of herd immunity through vaccines, while other parts of the world were left far more exposed to new mutations.