WHO experts meet to review efficacy of AstraZeneca vaccine

Geneva, Switzerland | Xinhua | Experts from the World Health Organization (WHO) met on Monday to review the efficacy of the Oxford-AstraZeneca vaccine against COVID-19, after a study showed it was less effective against a new variant, according to WHO Director-General Tedros Adhanom Ghebreyesus.

Earlier on Sunday, South Africa, where the new variant, B.1.351, was found, announced that the rollout of the AstraZeneca vaccine in the country would be temporarily put on hold until more clinical efficacy information becomes available.

At Monday’s WHO press briefing, Tedros said although the Oxford-AstraZeneca vaccine is one of the several that have been shown to be effective in preventing severe disease, hospitalizations and deaths from COVID-19, the emergence of new variants of the virus has raised concerns about their potential impacts on the efficacy of vaccines.

He announced that the WHO Strategic Advisory Group of Experts on Immunization (SAGE) has met to review the Oxford-AstraZeneca vaccine and discuss these new developments. Tedros noted that he will meet with the chair of SAGE on Tuesday to discuss its recommendations.

Also at the briefing, Kate O’Brien, director of the Department for Immunization, Vaccines, and Biologicals at the WHO, said SAGE had met with investigators from the trials being conducted in Britain and Brazil, as well as AstraZeneca and investigators from South African trials.

In looking at evidence on the AstraZeneca vaccine across a number of trials, it is very clear that it has efficacy against severe disease, hospitalizations and deaths among different variants, said Dr. O’Brien, while admitting that “there are some indications of reduction in the efficacy, some more some less, depending on which variant, which population, and also the neutralizing antibody responses.”

“But we also have evidence that there is the likelihood that the retention of meaningful impact against severe disease is a very plausible scenario for the product against the B.1.351 variant,” she added.

O’Brien also noted that “we really have to sort of sail a steady ship, based on the preponderance of evidence and not lurch from one particular report or another report.”

Meanwhile, the GAVI, a global Vaccine Alliance and a major player in the WHO-led COVAX initiative for COVID-19 vaccines, has decided to continue to roll out the AstraZeneca vaccine.

According to GAVI CEO Seth Berkley, the AstraZeneca vaccine is efficacious and has been reviewed and approved by a number of stringent regulatory authorities.

“Therefore we suspect that we will continue to roll that out, and we’ll continue to follow the effects of that vaccine over time,” Berkley said.

WHO has been pushing forward the COVAX initiative which is expected to include a large portfolio of COVID-19 vaccine products in the future.

Last week, China decided to provide 10 million COVID-19 vaccine doses to COVAX in response to the urgent needs of developing countries. According to WHO Chief Scientist Soumya Swaminathan, China has several vaccines under development and the WHO is speaking with all the developers.

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Xinhua