The newly identified variants, which appear to be significantly more infectious than the strain that emerged in China in 2019, come at a time when the increase in the number of viruses forces many nations to impose new blocks.
The committee normally meets every three months, but WHO said the director-general anticipated the meeting “to consider issues that need to be discussed urgently”.
“These are the variants and recent considerations on the use [of] vaccination and test certificates for international travel, “the global body said on Wednesday.
Mutations in Sars-CoV-2 are raising concerns among scientists who are struggling to find out whether they will respond to vaccines.
In particular, a mutation, initially detected in South Africa and in subsequent variants in Brazil and Japan, raised the alarm among researchers, who are studying the variant, known as 501Y.V2, to determine whether current vaccines will be effective.
Experts say vaccines will most likely still work against the new variants. Studies to confirm are ongoing, but these experiments take time.
Professor of infectious diseases at the University of Cape Town, Marc Mendelson, told ABC News that it is not yet known whether the South African variant is really 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. The evidence is supported by the speed of the increase in the number of infected people during the second wave. , both in South Africa and the United Kingdom, which has a separate variant that also carries the same mutation at position 501 in the peak protein “, Mendelson, who is also head of the Infectious Diseases and HIV Medicine Division at City Groot from Cabo Hospital Schuur, he told ABC News.
Mendelson said that a lot of urgent work is underway to study the mutation and he hopes that some answers will be provided in the coming weeks. “The most pressing question is whether mutations in the variant will affect responses to the vaccine. Then, there is the question of whether the variant is associated with more serious illnesses? I’m not seeing evidence of this on the ground (in my hospital), but subtle differences need to of too much data to be detected, so it’s anecdotal evidence. However, at the moment, there is no sign that they cause more serious illness. “
A preliminary study found that the Pfizer COVID-19 vaccine appears to work against the mutated virus, but further studies are needed because the South African variant has a number of additional mutations, including changes in some of the virus’s spike protein.
According to Mendelson, the spike protein is not only vital for the entry of the virus, but also the target site for antibodies that humans produce to control viral infection. “Simply put, these antibodies neutralize the virus by binding to specific sequences of the spike protein, preventing it from binding to a receptor in our cells and therefore preventing entry. If you can prevent the virus from entering cells, you can prevent that it replicates inhibits it from causing an infection. The cause 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 can reduce the binding of antibodies to their local recognition and therefore reduce the ability of our immune system to prevent the virus from entering cells and spreading. “
According to the WHO, the strain identified in South Africa was found in 20 countries, territories and areas after it was first reported to WHO on 18 December.
“From preliminary and ongoing investigations in South Africa, it is possible that the 501Y.V2 variant is more transmissible than the variants that were circulating in South Africa previously,” said the agency’s weekly report.
“Furthermore, while this new variant does not appear to cause more serious illness, the rapid increase in the number of cases seen has put health systems under pressure.” The geographical distribution of both variants is likely to be underestimated, the WHO said.
Fears about the increased transmissibility of the new variants are leading to new blockages and extra measures to contain COVID-19.
The South African strain is causing more concern, however, due to an additional mutation that puts scientists on edge, a so-called E484K, that could make certain vaccines less effective.
The WHO also noted that a third new variant of the “worrying” coronavirus, 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 that we should expect more variants to emerge,” said the WHO. SARS-CoV-2 is the virus that causes COVID-19 disease. Viruses constantly undergo small changes as they spread from person to person.
More than 90 million COVID-19 infections have been reported worldwide since the cases first appeared in December 2019. The number of deaths from the pandemic is almost two million people.