The World Health Organization (WHO) has recommended the use of AstraZeneca (AZ)/Oxford University’s COVID-19 vaccine in adults of all ages.
The WHO’s Strategic Advisory Group of Experts (Sage) has backed use of the jab in adults, including those aged over 65, despite some EU countries having already ruled out giving the vaccine to people in this age group.
Although there is limited data on the efficacy of the AZ/Oxford vaccine in the elderly, the jab has been found to trigger protective antibodies and T cell responses in older age groups.
AZ is currently conducting a large-scale clinical trial of the vaccine, which includes a significant proportion of people aged over 65.
The Sage panel has also recommended that the vaccine should be administered as two doses, given eight to 12 weeks apart.
“The efficacy of the vaccine is higher when the second dose is administered later,” said Joachim Hombach, executive secretary of the WHO’s Sage.
“You can expect to see a higher efficacy if you administer the vaccine in our recommended schedule which is eight to 12 weeks between doses,” he added.
Last week, South Africa (SA) halted the roll-out of the AZ/Oxford COVID-19 vaccine after new study results showed that the jab provides ‘minimal’ protection against the SA variant.
The study, conducted by researchers from the University of Witwatersrand and Oxford University, found that a two-dose regimen of the vaccine – also known as ChAdOx1 nCoV-19 – provides only minimal protection against mild-to-moderate COVID-19 caused by the SA or B.1.351 variant.
The research included approximately 2,000 volunteers with mild disease, which is defined as having at least one symptom of COVID-19.
The study did not assess the AZ/Oxford vaccine’s ability to protect against moderate-to-severe disease caused by the SA variant.
In response to these results, the WHO’s director for its department of immunisation Katherine O’Brien said that the AZ/Oxford vaccine should still prevent severe disease and death caused by the variant.
“Even if the efficacy drops down to as low as 10%, it is still the right thing to do to immunise older adults because of the higher risk of severe disease and mortality in that age group,” she commented.
“The new guidance from WHO is an important milestone in extending access to the Oxford-AZ vaccine to all corners of the world and providing further endorsement that after rigorous scrutiny by the WHO Strategic Advisory Group of Experts the vaccine can be used to help protect populations from the coronavirus pandemic,” said Andrew Pollard, chief investigator of the Oxford vaccine trial.