It is too early to write off the AstraZeneca COVID-19 vaccine because more data is needed, UN health experts have said, in reaction to a new study indicating its limited effectiveness against the South African variant.
Research by Oxford University in Britain and Witwatersrand University in South Africa has found the AstraZeneca vaccine is markedly less effective in protecting against milder forms of COVID-19 that stem from the mutation first detected in South Africa.
“This is clearly concerning news,” World Health Organisation chief Tedros Adhanom Ghebreyesus told a press briefing in Geneva on Tuesday morning (Australian time).
However, he stressed that the study was based on a trial with a small number of largely young participants.
“We mustn’t start concluding that this vaccine doesn’t work at all,” said WHO chief scientist Soumya Swaminathan.
She said the available evidence shows that this vaccine reduces deaths, hospitalisation and severe disease.
South African health authorities earlier halted plans for the rollout of the AstraZeneca vaccine to frontline workers and would instead start using shots by US firm Johnson and Johnson.
“We don’t want to end up with a situation where we have vaccinated a million people or two million people with a vaccine that may not be effective,” said Salim Abdool Karim, a senior health adviser to the South African government.
But he said South Africa might further test the AstraZeneca vaccine by giving it to only 100,000 people and monitoring hospitalisation rates.
The AstraZeneca vaccine forms the backbone of WHO’s plans to help immunise people in poorer countries that have not been able to secure priority supplies from pharmaceutical companies.
Britain will continue to administer the AstraZeneca vaccine despite the new study, the country’s vaccine minister said on Tuesday (Australian time).
Nadhim Zahawi wrote in The Telegraph newspaper that the British government has “confidence” in its current vaccine rollout plan and in the “protection it will provide all of us against this terrible disease.”
Meanwhile, French Health Minister Olivier Veran received the first injection of the AstraZeneca vaccine at a hospital near Paris, arguing it was providing enough protection against almost all virus spreading in the country.
France received its first batch of AstraZeneca vaccines last week, representing 273,600 doses all reserved for health professionals under 65.
Mr Veran said “at least 99 per cent” of the virus circulating in France do not correspond to the variant widely spread in South Africa, which makes the AstraZeneca vaccine effective on the French territory.