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The South African government is suspending the use of one of its COVID-19 vaccines in its citizens because it is ineffective against a mutated strain of the coronavirus known as B.1.351.
The government announced Sunday that the SARS-CoV-2 vaccine developed by the pharmaceutical company AstraZeneca and the University of Oxford did not protect clinical trial volunteers from B.1.351, a more contagious mutant strain of the new coronavirus.
South Africa is therefore suspending use of that vaccine, although they said they would reconsider its use if additional studies bolster existing ones that suggest the vaccine could protect people against more severe cases. The government’s challenge is that the existing studies included volunteers who were younger and less likely to develop serious infections, which means they were unable to determine this for themselves. The reliability of the studies is also hampered by the fact that they did not analyze a large number of cases.
“There is a lot of uncertainty, but this is not good news, especially for countries that were hoping to use the Oxford / AstraZeneca vaccine to slow the transmission of B.1.351,” Dr. Dylan Morris, a postdoctoral researcher at UCLA, told Salon by email. “It is still possible that the Oxford / AstraZeneca vaccine reduces the severity of B.1.351 infection, and it is still possible that it works better with a longer dose gap. Scientists are investigating.”
He struck a cautiously upbeat note, telling Salon that South African scientists also found that a Johnson & Johnson one-shot vaccine “showed efficacy against B.1.351 in a large clinical trial. It prevented symptoms well and severe disease very well. “. and that although there has been no clinical trial for the mRNA vaccines, “the laboratory evidence gives us reason to be cautiously optimistic that they will remain more like J&J than Oxford / AstraZeneca.” It also noted that South African scientists based their conclusion in part on the laboratory results of the Oxford / AstraZeneca vaccine as “substantially worse” than other vaccines, meaning that their decision to implement the Johnson & Johnson vaccine is “very prudent”. . “
The news may bode ill for vaccination in South Africa, but it doesn’t mean that the US mass vaccination strategy needs to be changed – yet.
“The low efficacy of variant B.1.351 shows how much we need to avoid further mutations and control this pandemic as soon as possible with vaccines and mitigation strategies together,” said Dr. Eric Feigl-Ding, principal investigator for the American Federation. The scientists told Salon by email. He noted that “other vaccines will work for variant B.1.351 even if AstraZeneca doesn’t.”
“We are fortunate that B.1.351 is still relatively rare in the US, but we know that the most infectious UK B.1.1.7 variant is in the US and it is increasing rapidly; it is likely that becomes the dominant variant in mid to late March, “he added.
The B.1.1.7 strain of the new coronavirus, which originated in the UK and was first identified in September, is notable in that it is unusually transmissible, has an abnormally large number of mutations (23), and has some of those mutations. in Spike protein. The Spike protein is what causes the tiny dots on the surface of the virus, like the spines of a sea urchin, that the virus uses to enter the cells of the body, and that mRNA vaccines such as those developed by Pfizer and Moderna they aim to inoculate people. against disease.
The South African B.1.351 mutation, by contrast, is known to develop an additional mutation known as E484K, which appeared to correlate with vaccines that are less effective in South Africa. In the UK, at least 11 individual B.1.1.7 viruses also had the E484K mutation.
“Much of the growth of this variant has been hidden in the background of the decline of the old common strain,” Feigl-Ding wrote to Salon. “We can’t be complacent. Vaccines work; we need to use the critical time window now to slow and stop transmission before wave B.1.1.7 crashes as the dominant variant in the United States.”
Morris voiced a similar view, writing that “Americans are fortunate to have access to excellent vaccines – mRNA vaccines, and possibly soon [Johnson & Johnson]. But the variants remain a great threat to Americans. All three are already here, and it is quite possible that all three are more transmissible than the wild type. That makes it more difficult to control the pandemic while we vaccinate, as places like the UK and Israel have seen. “
Dr. Russell Medford, president of the Center for Innovation in Global Health and the Center for Crisis Coordination for Global Health, wrote to Salon that the new information from South Africa illustrates three important points for the American people.
“First, it is fortunate that we have many other vaccines, such as those developed by Pfizer, Moderna, Novavax, and Johnson and Johnson, that preliminary laboratory studies show to be somewhat less effective but still protective against B.1.351,” Medford explained. “Second, when necessary, the technology underlying mRNA vaccines allows for the rapid development of vaccine boosters that can specifically protect against variants such as B.1.351.”
He added: “Third, to prevent the spread of B.1.351 and the emergence of new and similar variants, we can and must aggressively and rapidly crush the circulation of the SARS-CoV2 virus, including all its variants, by mass vaccination and rigorous adherence to the use of masks, social distancing and hand washing “.
