WHO expert group to make recommendations on AZ-Oxford vaccine

An expert group reviewing the Covid-19 vaccine from the AstraZeneca-Oxford University combine will convey its recommendation for the use of this product to the World Health Organization Chief Dr Tedros Adhanom Ghebreyesus on Tuesday.

SAGE or the WHO’s Strategic Advisory Group of Experts on Immunisation met on Monday “to review evidence on the AstraZeneca/Oxford vaccine, including emerging evidence on performance against viral variants, and to consider the demonstrated impact of the product and the risk-benefit assessment for use cases with limited data,” a note from Covax, a WHO-supported vaccine initiative said.

The development comes as more countries limit the age at which the AZ-Oxford Covid-19 vaccine is administered, to 65 years. Spain and Belgium went one step further and stopped at 55 years, according to reports. Meanwhile, South Africa stopped giving this vaccine, after a study showed it was minimally effective at preventing mild to moderate disease caused by a variant first identified in South Africa.

“This is clearly concerning news. However, there are some important caveats,” said Dr Tedros. “Given the limited sample size of the trial and the younger, healthier profile of the participants, it is important to determine whether or not the vaccine remains effective in preventing more severe illness,” he added.

The WHO is expected to decide on the emergency use listing of the Oxford-AZ vaccine in the next few days, for the two sites in India and the Republic of Korea which will produce it for COVAX, he said.

Covax has an agreement on the AZ-Oxford vaccine to distribute nearly 350 million doses in the first half of the year. Serum Institute of India will make and distribute the vaccine in low and middle income countries.

The Oxford-AstraZeneca vaccine is one of several that has been shown to be effective in preventing severe disease, hospitalisation and death from Covid-19, Dr Tedros and other experts addressing the media said.

‘Suppressing transmission’

“Several countries are succeeding in suppressing transmission, including those where new variants are circulating,” he said, adding that manufacturers too would have to adjust to the evolution of the virus, taking into account the latest variants for future shots, including boosters.

“We know viruses mutate and we know we have to be ready to adapt vaccines so they remain effective. This is what happens with flu vaccines, which are updated twice a year to match the dominant strains,” he said.

While the WHO has an existing mechanism to track and evaluate variants of the virus, countries too need to report these variants to the WHO, so they could globally coordinate and advise countries accordingly, he said.

“These developments highlight why it’s so important to scale up manufacturing and roll out of vaccines as quickly as possible and as widely as possible to protect people before they are exposed to new variants,” he added.

Additional studies

Meanwhile, the Covax note said, that additional studies were being funded by CEPI (Coalition for Epidemic Preparedness Innovations) “to optimize and extend the use of existing vaccines, which could include “mix-and-match” studies of different vaccines used in combinations that may improve the quality and strength of the immune response.”