New COVID-19 variant defeats plasma treatment and could reduce vaccine effectiveness

JOHANNESBURG (Reuters) – The new COVID-19 variant identified in South Africa may escape antibodies that attack it in treatments using blood plasma from previously recovered patients, and may reduce the effectiveness of the current range of vaccines, have scientists said Wednesday.

Researchers are rushing to determine whether vaccines currently being deployed around the world are effective against the so-called 501Y.V2 variant, identified by South African genomics experts late last year in Nelson Mandela Bay.

“This line shows a complete escape of three classes of therapeutically relevant monoclonal antibodies,” wrote the team of scientists from three South African universities working with the National Institute for Communicable Diseases (NICD) in an article published in the journal bioRxiv .

“Further, 501Y.V2 shows substantial or complete escape of neutralizing antibodies in convalescent COVID-19 plasma,” they wrote, adding that their findings “highlight the prospect of reinfection … and may herald reduced efficacy of current peak-based vaccines. “

The 501Y.V2 variant is 50% more infectious than the previous ones, South African researchers said this week. It has already spread to at least 20 countries since it was reported to the World Health Organization in late December.

This is one of the many new variants discovered in recent months, including others first found in England and Brazil.

The variant is the main driver of the second wave of COVID-19 infections in South Africa, which reached a new daily peak above 21,000 cases earlier this month, well above the first wave, before to drop to around 12,000 per day.

Convalescent blood plasma from previous patients has not been shown to be effective when given to critically ill patients requiring intensive care for COVID-19, but it is approved in several countries as an emergency measure.

British scientists and politicians have expressed concern that vaccines currently deployed or under development may be less effective against the variant.

The paper says it remains to be seen how effective current vaccines are against 501Y.V2, which will only be determined through large-scale clinical trials. But the results showed the need to design new vaccines to combat the evolving threat, he said.