Pope Francis is adding his voice to a campaign to overcome vaccine scepticism, issuing a public service announcement insisting that vaccines are safe, effective and an "act of love."

       The video message released Wednesday is aimed at a global audience but directed particularly at the Americas. It features six cardinals and archbishops from North, Central and South America as well as the Argentine-born pope. It was produced by the Vatican and the Ad Council, which has produced a series of pro-vaccine ads in a bid to get more people vaccinated.

       In his comments, Francis said: “Being vaccinated with vaccines authorised by the competent authorities is an act of love. And contributing to ensure the majority of people are vaccinated is an act of love.”

       He added: “Vaccination is a simple but profound way of promoting the common good and caring for each other, especially the most vulnerable.”

       Francis had emphasized at the start of the pandemic the need to ensure equal access to the vaccine, especially for the poor. But faced with increasing skepticism about vaccines especially among religious conservatives, the Vatican has vowed an all-out effort to overcome hesitancy and encourage widespread vaccination.

       The Vatican has declared that it is morally acceptable for Catholics to receive COVID-19 vaccines, including those based on research that used cells derived from aborted foetuses.