Rolling out booster campaigns which target more than just vulnerable people is “really not right”, the director general of the World Health Organisation said.
Dr Tedros Adhanom Ghebreyesus urged countries rolling out such campaigns for the wider population to think twice.
He added there was still a lack of evidence to show booster jabs are needed.
Answering a question on third doses for TRT World at a WHO briefing focused on Africa and Covid-19 vaccine equity, Dr Tedros said: “The moratorium for use for boosters, which I asked should last up to the end of this year, covers the immunocompromised specifically, not beyond that.
“We said it many times.
“We had a meeting recently of 2000 scientist coming from all over the world who discussed on the same issue and there is nothing conclusive on the use of boosters for the time being.
“Until we have conclusive evidence it’s very important to hold it.”
Dr Tedros added that there are ethical concerns with vaccinating protected people when others around the world have yet to receive a dose.
He said: “There are countries with less than 2% of vaccination coverage, most of them in Africa, who are not even getting the first and second dose and starting with boosters, especially giving it to healthy populations, is really not right.”
The director general referenced WHO executive director Dr Mike Ryan’s comparison of booster jabs for the non-immunocompromised as handing out life jackets to those who already have one.
Dr Kate O’Brien, the director of the department of immunisation, vaccines and biologicals at WHO added that evidence on boosters is still being collected.
She said: “One of the important points for people to really understand is that this is not about withholding booster doses in the face of evidence that they are needed.
“This is about needing evidence that they’re needed and that there is a safe pathway towards their deployment.
“We’ll continue to watch as that evidence accrues and make any adjustments as the evidence demands it, but we’re not there yet.”
From next week the UK will offer booster Covid vaccines to millions of people alongside annual flu jabs.
Those eligible include anyone aged 50 and over, people living and working in elderly care homes, and frontline health and social care workers.
All those who are clinically extremely vulnerable and anyone aged 16 to 65 in an at-risk group for Covid (who were included in priority groups one to nine during the initial vaccine rollout) will also be eligible for a jab.