The epidemic, which broke out in May in Europe, is currently in full decline, although the WHO recently decided to maintain its maximum alert level.
The monkeypox vaccine is 78% effective as early as two weeks after the first dose, according to data from the UK Health Security Agency released on Monday.
The study looked at 363 cases of monkeypox recorded in England between July 4 and November 3 among the vaccine-eligible population (including men who have sex with men).
78% efficiency after 14 days
Of these cases, only eight had been vaccinated at least two weeks before becoming ill and 32 had received a dose within 13 days of contracting the virus.
“This gives an estimated vaccine efficacy for a single dose of 78% after 14 days,” health agency UKHSA said in a statement on Tuesday.
“We now know that a first dose of vaccine provides strong protection against monkeypox,” said UKHSA epidemiologist Jamie Lopez-Bernal. And “even if the cases of monkeypox are few, it is vital to remain vigilant about the risks”, he warned.
55,000 doses administered in the UK
For his part, the head of vaccinations at the public health service NHS, Steve Russell, indicated that “more than 55,000 doses of vaccines have already been administered” in England.
The vaccine from the Bavarian Nordic laboratory, marketed under the name Jynneos in the United States, is the only one approved specifically against monkeypox. It is given in two doses, 28 days apart.
In September, US data had already highlighted that this vaccine was very effective from the first dose, highlighting that unvaccinated people were 14 times more likely to be infected with monkeypox than those vaccinated.
The disease – endemic in some West African countries – is characterized by rashes, which may appear on the genitals or in the mouth, and may be accompanied by bouts of fever, sore throat or pain in the lymph nodes.
From May, health authorities noted outbreaks in Europe and the United States, but the epidemic is now in full decline.
According to updated figures as of November 21, 3,570 confirmed cases and 150 highly probable cases have been identified in the UK.