The AstraZeneca-Oxford Covid-19 vaccine can be used for people aged over 65, and also where coronavirus variants of concern are circulating, WHO experts said Wednesday, soothing fears about the jab.
The World Health Organization's 15-member Strategic Advisory Group of Experts on Immunization (SAGE) issued interim recommendations for when and how to use the two-shot vaccine, which has yet to receive WHO emergency use authorisation.
The announcement came after the vaccine suffered several setbacks, raising questions about whether it was appropriate to use it on older people, or in places where a variant of the virus first found in South Africa is circulating.
SAGE chief Alejandro Cravioto acknowledged the lack of data on the vaccine's efficacy for people aged over 65, which has prompted a number of countries to withhold recommending its use in older people -- who are by far the most vulnerable to the virus.
But, he told journalists, "we feel that the response of this group cannot be any different from groups of a younger age".
SAGE, he said, recommends "for the vaccine to be used for 18 years and above without an upper age limit".
He said the experts were eagerly awaiting more specific data on the efficacy of the vaccine in people over 65, but said it "would not be appropriate" to wait with its recommendations.
"We have thousands of people dying," he stressed.
"Anything we can do to use a product that might reduce that is totally justified, even if the information is not as complete as we would like."
- Effectiveness against variants -
The experts also said they had discussed the effectiveness of the vaccine when faced with a range of new virus variants of concern, and in particular the one first spotted in South Africa.
The country has decided to put off using AstraZeneca jabs in a planned vaccination programme over concerns about their efficacy against the variant.
Alarm was raised when a South African study concluded the AstraZeneca vaccine provided only "minimal" protection against mild to moderate Covid-19 caused by the variant.
But the WHO urged caution, pointing to the small size and possibly problematic methodology of the study, insisting more data was needed.
And SAGE said Wednesday the vaccine could also be used in places where "variants are present".
Cravioto stressed that "there is no reason not to recommend its use even in the countries that have the circulation of the variants".
The experts also said the vaccine proved more effective when the interval between the doses was extended to between eight and 12 weeks.
They also reiterated their recommendation not to prioritise international travellers for vaccination.
- Equitable distribution -
SAGE, which advises the WHO on overall global vaccine policies and strategies, has already issued advice on the usage of the Pfizer-BioNTech and the Moderna vaccines.
AstraZeneca's vaccine is currently a vital part of Covax, the system set up by WHO and others to procure Covid-19 jabs and ensure their equitable distribution around the world.
It accounts for almost all of the 337.2 million vaccine doses Covax is preparing to begin shipping to some 145 countries during the first half of the year, once it receives WHO authorisation.
Andrew Pollard, from Oxford University's Vaccine Group, said: "The new guidance from WHO is an important milestone in extending access to the Oxford-AZ vaccine to all corners of the world."
The WHO is set to decide next week on whether to give the AstraZeneca vaccine emergency use authorisation for doses produced in India and South Korea.
If granted, those doses could start to be distributed to some of the world's poorest countries via Covax.
So far, the WHO has only given emergency use listing to the Pfizer jab, though several other manufacturers have started the evaluation process.