The World Health Organization on Monday authorized the use of the AstraZeneca-Oxford vaccine, clearing a path for the cheap and easy-to-store shots to be distributed in lower- and middle-income countries around the world.
A small clinical trial in South Africa recently failed to show that the vaccine could keep people from getting mild or moderate cases of Covid-19 caused by a coronavirus variant spreading there. But that vaccine had protected all participants against severe disease and death in other trials and may yet prevent severe disease and death caused by the variant first detected in South Africa.
The authorization, expected after a panel of W.H.O. experts recommended use of the vaccine last week, applied to the vaccine’s two manufacturers: AstraZeneca and the Serum Institute, the Indian producer that will supply many doses for the Covax initiative to bring vaccines to poorer parts of the world.
The W.H.O. last year authorized the Pfizer-BionNTech vaccine. But its decision on AstraZeneca’s vaccine has been highly anticipated, because the low price and easy storage requirements have made the vaccine the backbone of rollout plans in many countries around the world.
“Countries with no access to vaccines to date will finally be able to start vaccinating their health workers and populations at risk, contributing to the Covax Facility’s goal of equitable vaccine distribution,” Dr. Mariângela Simão, the W.H.O. assistant-director general for access to medicines and health products, said in a statement.
The W.H.O. panel of experts recommended that the AstraZeneca vaccine be used in all adults, and in countries where concerning new variants are circulating. Countries are expected to begin receiving their first tranches of the AstraZeneca vaccine from Covax later in February.
In announcing the authorization for the vaccine on Monday, Dr. Tedros Adhanom Ghebreyesus, the director-general of the W.H.O., said that while virus cases appeared to be falling in many parts of the world, countries needed to remain vigilant.
“If we stop fighting it on any front,” he said, “it will come roaring back.”
After the results of the small clinical trial of the AstraZeneca vaccine in South Africa were released, South Africa decided to pause plans to distribute it. Instead, South Africa was planning to inoculate health workers with the Johnson & Johnson vaccine, which prevented hospitalizations and deaths in clinical trials in the country.
The W.H.O. panel that examined the AstraZeneca vaccine also advised that it be given to adults regardless of their ages, breaking with a number of European countries that have opted to restrict the use of the vaccine to younger people. And it recommended that the two doses of the vaccine be given between four and 12 weeks apart, citing evidence that the vaccine appears to work better when second doses are delayed.