Monkeypox cases could spiral by the end of the year – and reach children, for whom the virus can be deadly – if efforts to vaccinate against it are not improved, experts have warned.

While 50,000 vaccine doses are on order, public health experts say four times this number will be needed to halt the spread.

In the UK, there have already been more than 1,850 cases of the disease, which causes painful blisters across the body, and numbers are believed to be doubling every 15 days. These have predominantly been seen in gay men.

Dr Deborah Birx, the former head of the US Covid task force, told The Mail on Sunday that all gay men in London under the age of 50 should be vaccinated as well as women who visit gay bars. ‘If you’re at a gay bar and you’re dancing, then there is a risk of infection,’ she said.