The World Health Organization said Thursday it remained unclear whether additional Covid-19 vaccine doses are needed to protect against the new Omicron variant, and urged wealthy countries to avoid hoarding the jabs.
The UN health agency's vaccine advisors warned that a rush to stockpile more jabs, especially without clear evidence they are needed, would only exacerbate the already glaringly inequal vaccine access around the globe.
"As we head into whatever the Omicron situation is going to be, there is a risk that the global supply is again going to revert to high-income countries hoarding vaccine to protect (their populations) ... in a sense in excess," WHO vaccines chief Kate O'Brien told reporters.
Her comment came after preliminary results published Wednesday indicated that three doses of the Pfizer-BioNTech Covid vaccine were needed to obtain the same level of protection against Omicron as two doses provided against the initial strain.
O'Brien said the WHO was examining the data, and that it may turn out that "additional doses have benefit to provide added protection against Omicron", but stressed it was still "very early days".
While there was still little evidence that additional doses were needed to protect against developing severe Covid disease, many vulnerable people and health workers in poorer nations have yet to receive a single dose and remain at great risk.
O'Brien pointed out that the world had only just begun addressing the dangerous inequity in vaccine access in the past two months, with more donated doses and large shipments going to underserved countries.
"We have to make sure that it continues," she said, warning that efforts by wealthy countries to stockpile more jabs for their people would only prolong the pandemic.
"It's not going to work from an epidemiologic perspective, and it's not going to work from a transmission perspective, unless we actually have vaccine going to all countries," she said.
"Where transmission continues ... is where the variants are going to come from," she warned, urging "a much more rational global perspective from countries about what's actually going to shut down this pandemic."