World Health Organization Director-General Dr Tedros Adhanom Ghebreyesus has expressed concern over news that South Africa has temporarily held the roll out of Oxford-AstraZeneca corona vaccine after it was seen as minimally effective against the new variant identified in the country.
The Oxford-AstraZeneca vaccine is one of several that has been shown to be effective in preventing severe disease, hospitalization and death from Covid. This vaccine has also been rolled out in India and is currently being given to healthcare workers across the country.
Ghebreyesus has said that South Africa announced it was putting a temporary hold on the rollout of the Oxford-AstraZeneca vaccine after a study showed it was minimally effective at preventing mild to moderate disease caused by a variant first identified in South Africa, he informed.
“This is clearly concerning news. However, there are some important caveats,” he said.
“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,” said the WHO-DG.
Dr Ghebreyesus has stressed that these results are a reminder that there is a need to do everything that can be done to reduce circulation of the virus with proven public health measures. Several countries are succeeding in suppressing transmission, including those where new variants are circulating,” he explained.
“We all have a role to play in protecting vaccines. Every time you decide to stay at home, to avoid crowds, to wear a mask or to clean your hands, you are denying the virus the opportunity to spread, and the opportunity to change in ways that could make vaccines less effective,” he said.
He has further pointed out that it also seems increasingly clear that manufacturers will 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,” said Dr Ghebreyesus.
“WHO has an existing mechanism for tracking and evaluating variants of the virus that causes Covid. It is vital that nations continue to report these variants to WHO, so we can coordinate global efforts to monitor their impact and advise countries accordingly,” he added.
Dr Ghebreyesus informed that WHO is now expanding that mechanism to provide guidance to manufacturers and countries on changes that may be needed for vaccines.
"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,” added Dr Ghebreyesus.
The WHO has advised that there is also a need to continue designing and conducting new trials, keep a close eye on the impact vaccines are having on epidemiology, severe disease and death so we can use vaccines to maximum effect,” he added.