The new coronavirus variant detected in SA in mid-December is about 50% more transmissible than older lineages but there is no evidence that it leads to more severe disease, one of health minister Zweli Mkhize’s top scientific advisers said on Monday.
However, scientists remain concerned about the capacity of the new variant, dubbed 501Y.V2, to render Covid-19 vaccines less effective because new research has found antibodies from a high proportion people who have previously been infected during SA’s first coronavirus wave were unable to neutralise it, said Salim Abdool Karim, who co-chairs the ministerial advisory committee on Covid-19.
The 501Y.V2 variant, along with the B117 lineage detected in the UK in mid-December, have scientists worried, because they contain mutations in the spike protein that the SARS-CoV-2 virus uses to gain entry into human cells.
The extremely rapid spread of these more contagious variants not only threatens to overwhelm already strained health systems, but has scientists deeply concerned that the vaccines already being administered will be rendered less effective.
The variants could also throw a spanner in the works for other shots that are still in clinical trials. A safe and effective vaccine is widely regarded as the best hope for ending the coronavirus pandemic, which has led to more than 95-million recorded cases, and 2-million deaths since it emerged in China little more than a year ago.
Governments that have begun administering vaccines are now racing to immunise as many people as possible, hoping to reach them before they encounter the new variants. A rapidly growing epidemic also increases the risk of more, and potentially problematic, mutations.
Concerns about the contagious nature of 501. V2 and its potential to be less susceptible to vaccines have prompted a growing list of countries to limit travel to and from SA, and introduce new testing and quarantine protocols. The SA variant has been found in more than 20 countries since it was reported to the World Health Organisation on December 18, while the B117 variant has been identified in over 50 countries since mid-December.
SA is grappling with a sharp resurgence in coronavirus infections, which by Sunday had topped 1.34 million cases and 37,100 deaths. About a third of the recorded cases and deaths have occurred in the past four weeks.
Speaking during a scientific seminar hosted by the health minister, Karim said the coronavirus was spreading about 50% faster in the second wave than it had in the first in the coastal provinces, where 501Y.V2 is known to be the dominant strain.
Researchers from the National Institute of Communicable Diseases found the 501Y.V2 variant was able to evade the antibodies generated by people in SA’s first coronavirus wave in almost half the 44 samples they studied. They also found 90% of these antibody samples were less effective at neutralising 501Y.V2 than older lineages.
“There are limitations to this data, and we need to wait for clinical trial data (and other studies) to determine whether or not this will impact on vaccines,” said NICD senior scientists Penny Moore.
Koleka Mlisana, head of research and quality assurance at the National Health Laboratory Service, said there was no evidence of an increased risk of reinfection with the new variant.
Tulio de Oliveira, director of the KwaZulu-Natal research and innovation sequencing platform, said it was vital to slow the spread of the coronavirus. “If we cannot stop transmission, we are likely to see a third or fourth wave, and a virus better able to evade the immune response,” he said.
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