The new variants identified, which appear to be significantly more infectious than the strain that appeared in China in 2019, are coming as the growing number of viruses is forcing many nations to impose new blockades.
The committee normally meets every three months, but the WHO said the director-general had postponed the meeting “to consider issues that needed urgent discussion”.
“These are recent variations and considerations for use [of] vaccination and testing certificates for international travel, “the global body said on Wednesday.
The Sars-CoV-2 mutations raise concerns among scientists who are struggling to figure out if they will respond to vaccines.
In particular, a mutation, initially detected in South Africa and later in Brazil and Japan, has raised alarm among researchers studying the variant, known as 501Y.V2, to determine whether current vaccines will be effective.
Experts say the vaccines will most likely work against the new variants. Confirmatory studies are ongoing, but these experiments take time.
Cape Town University professor of infectious diseases Marc Mendelson told ABC News that it remains unclear whether the South African version is indeed more contagious. “Studies to date suggest that people infected with this variant have an increase in viral load, which is likely to increase that person’s ability to transmit to others. , in both South Africa and the United Kingdom, which has a separate variant that also bears the same mutation at position 501 in the protein spike, “Mendelson, who is also the head of the Infectious Diseases Division and HIV medicine at Cape Town’s Groote Schuur Hospital, told ABC News.
Mendelson said there is a lot of urgency going on to study the mutation and hopes there will be some answers in the next few weeks. “The most pressing question is whether the mutations in the variant will affect the vaccine responses. Then there is the question of whether the variant is associated with a more severe disease? I don’t see any evidence of this on the ground (at my hospital), but the subtle differences need a lot of data to take over, so this is anecdotal evidence. However, at present, there is no sign that it would cause more severe diseases. “
A preliminary study found that the Pfizer COVID-19 vaccine appears to work against the mutant virus, but more studies are needed because the South African version has a number of additional mutations, including changes in some of the virus’s peak proteins.
According to Mendelson, spike protein is not only vital for the entry of the virus, but is also the target of antibodies that humans produce to control viral infection. “These antibodies simply neutralize the virus by binding to specific spike protein sequences, preventing it from binding to a receptor on our cells and therefore preventing entry. If you can prevent the virus from entering the cells, you can prevent reproduction, and the reason for concern is again, a series of mutations in the genetic code of the virus that the variant has. The resulting changes in the structure of the spike protein could reduce the binding of antibodies to their site recognition and therefore reduce the ability of our immune system to prevent the virus from entering cells and trapping. “
According to the WHO, the strain identified in South Africa was found in 20 countries, territories and areas after it was first reported by the WHO on 18 December.
“From preliminary and ongoing investigations in South Africa, the 501Y.V2 variant may be more transmissible than the variants previously circulating in South Africa,” the agency’s weekly report said.
Moreover, while this new variant does not appear to cause more severe diseases, the rapid increases observed where the number has put health systems under pressure. The geographical spread of both variants is probably underestimated, the WHO said.
Fears about the increased transmissibility of the new variants lead to new blockages and additional measures to contain COVID-19.
However, the strain in South Africa is a cause for concern, due to an additional mutation that scientists have at hand, one called E484K, which may make some vaccines less effective.
The WHO also mentioned that a third new variant of coronavirus “of concern”, found in Japan, needs further investigation.
“The more the SARS-CoV-2 virus spreads, the more opportunities it has to change. High levels of transmission mean we should expect more variants to appear,” the WHO said. SARS-CoV-2 is the virus that causes COVID-19 disease. Viruses constantly undergo minor changes as they spread from person to person.
More than 90 million COVID-19 infections have been reported globally since cases first appeared in December 2019. The death toll from the pandemic is close to two million.