'We can't vaccinate the planet every six months,' says Oxford vaccine scientist

(CNN)A leading expert who helped create the Oxford-AstraZeneca Covid-19 vaccine said Tuesday that giving everyone in the world booster shots multiple times a year is not feasible.

"We can't vaccinate the planet every four to six months. It's not sustainable or affordable," Professor Andrew Pollard, the director of the Oxford Vaccine Group and head of the UK's Committee on Vaccination and Immunization, told The Daily Telegraph in an interview published Tuesday.

Pollard also stressed the "need to target the vulnerable" going forward, rather than administering doses to everyone age 12 and older. More data is needed to ascertain "whether, when and how often those who are vulnerable will need additional doses," he said.