Leaders need to start building trust in communities around the world about the critical importance of vaccinating people, Francesco Rocca said.
Mr Rocca said there was "a growing hesitancy about vaccines in general, and about a Covid vaccine in particular”. He pointed to a recent Johns Hopkins University study in 67 countries that found vaccine acceptance declined significantly in most countries from July to October this year.
He added: "To beat this pandemic, we also have to defeat the parallel pandemic of distrust."
In a quarter of countries, Mr Rocca said, the study found the acceptance rate for a vaccine against the coronavirus was near or below 50 per cent, with Japan dropping from 70 per cent to 50 per cent, and France dropping from 51 per cent to 38 per cent acceptance.
He said the lack of trust "is by no means a Western phenomenon," citing the federation's research in recent months in eight African countries - Congo, Cameroon, Gabon, Zimbabwe, Sierra Leone, Rwanda, Lesotho and Kenya - which showed a steady decline in the perceptions of the risk of Covid-19 infection.
A growing number of people thought that the virus does not affect young people or Africans, that the disease does not exist now but did exist and the pandemic has ended, he told the UN Correspondents Association.
He said: "In several African countries, we have seen a common scepticism towards vaccines in general, with a common belief being that foreigners use Africa as a medical testing ground."
Surprisingly, Mr Rocca said, some typically vulnerable and marginalised groups are not even aware of the pandemic, pointing to a federation survey in Pakistan which found 10 per cent of respondents did not know about Covid-19.
"We believe that the massive, coordinated efforts that will be needed to roll out the Covid vaccine in an equitable manner need to be paralleled by equally massive efforts to proactively build and maintain trust," he said.
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