South Africa Corona Virus - Antibodies

Research by South African scientists suggests that antibodies triggered by exposure to the country’s dominant coronavirus variant can prevent infection by other variants.

The findings in laboratory studies offer hope that COVID-19 vaccines based on the 501Y.V2 variant first identified late last year could protect against multiple mutations circulating in different parts of the world, scientists said on Wednesday.

The more contagious variant drove the second wave of infections in South Africa that peaked in January and is believed to have spread to many other countries in Africa as well as other continents.

“We used plasma … from people that were infected in this latest wave with the 501Y.V2 and we used it against the first-wave virus, … what we found is that it could neutralise, OK not as well as it could neutralise itself but it’s not bad at all,” Alex Sigal from the Africa Health Research Institute told a news conference.

The findings have yet to be peer-reviewed by researchers.

Sigal said vaccines designed with the 501Y.V2 version in mind “might be cross-protective to other variants, … this gives you some idea how this problem of variants can be solved”.

Top virologist Tulio de Oliveira also said in the video conference attended by senior government ministers that “the 501Y.V2 can produce a high level of antibodies that can neutralise itself,”, adding that the immune response outperforms previous variants.

‘Good prospect of success’

Penny Moore, a professor at the National Institute for Communicable Diseases, said the antibody response from the 501Y.V2 variant was only reduced threefold against the first-wave virus, whereas the response from the first-wave virus was reduced nine-fold against 501Y.V2, which is also known as B1351.yes

“It’s not that the antibodies that are triggered by 501Y.V2 are somehow magical, there is a drop-off, but unlike the antibodies triggered by the original variant they seem to somehow have a little bit more breadth,” she told the same briefing.

Salim Abdool Karim, a top government adviser on COVID-19, said big vaccine manufacturers including Pfizer, AstraZeneca and Johnson & Johnson were already making vaccines based on the 501Y.V2 variant.

He predicted that by the end of 2021 most vaccine manufacturers would have adapted their shots, “not because they are specifically worrying about the virus coming from South Africa … but because key mutations in the 501Y.V2 are actually also present in many other variants”.

“These findings are basically telling us that we have a good prospect of success if we make a vaccine based on it,” he said.


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