The EU Agency for Infectious Diseases is recommending that member states develop strategies for possible vaccination programs to counter rising cases of monkeypox as evidence of community transmission of the disease mounts.
The European Center for Disease Prevention and Control (ECDC) said in response to questions on Sunday that it would make the recommendation in a risk assessment due to be published on Monday. Any vaccination campaign would use the existing smallpox vaccine, as there is no approved monkeypox vaccine, and would involve immunizing close contacts of confirmed monkeypox patients.
Smallpox immunity has been shown to provide some cross-protection against monkeypox. Smallpox was declared eradicated in 1980, but stocks of vaccine were maintained to guard against a possible resurgence.
The Stockholm-based ECDC noted that recommending smallpox vaccination for close monkeypox contacts at this time was “not an easy decision” and said a risk-benefit analysis should be carried out for each affected individual. The vaccine available in the EU, Danish drugmaker Bavarian Nordic’s Imvanex, is not approved for use against monkeypox, and there is no safety data on its use in people with compromised immune systems or in young children who are most at risk of the disease, he said the ECDC.
The approach known as post-exposure prophylaxis is recommended because the disease spreads among individuals with no known links to another confirmed case or affected region, known as community transmission.
The vaccine is also available in the UK, where health officials have recommended a similar strategy.
Scientists and health officials are scrambling to better understand the outbreak, the largest yet outside of areas where it’s endemic. As of Saturday, 92 laboratory-confirmed cases from 12 countries where the virus does not normally circulate had been reported to the WHO.
Israel, Austria and Switzerland said they confirmed their first cases on Sunday.
Monkeypox is a viral disease and most cases, if not all, have been seen in men who have sex with men. According to the ECDC, human-to-human transmission occurs primarily through large respiratory droplets. Since these droplets do not travel far, prolonged contact is required. The virus can also be transmitted through other body fluids. Health authorities are trying to rule out aerosol transmission or the evolution of the virus into a more easily transmissible strain.
The World Health Organization said over the weekend that available information indicates transmission “occurs in people in close physical contact with symptomatic cases”. All laboratory-confirmed specimens to date have been confirmed to belong to the West African subfamily. So far, no related deaths have been reported.
Symptoms are flu-like and also include a rash that often starts on the face and then spreads to other parts of the body. Incubation can last up to 21 days, making contact tracing difficult.
“The situation is evolving and WHO expects more cases of monkeypox to be identified as surveillance expands in non-endemic countries,” the Geneva-based health agency added.
Shares of Bavarian Nordic, the maker of the smallpox vaccine, are up about 55 percent since May 19, when the number of cases in Europe began to rise. A European health official said “thousands” of Imvanex doses are readily available.
Bavarian Nordic did not immediately respond to a request for comment on Sunday.
Meanwhile, US President Joe Biden said on Sunday that the outbreak “is something everyone should be concerned about.” Speaking from South Korea, where he was on an official visit, he said the US is in the process of identifying a suitable vaccine to fight the virus.
Ashish Jha, the White House coronavirus response coordinator, told ABC on Sunday that the US had identified one case in Massachusetts and one in New York and was pursuing others. But he said this is “a virus that we understand” and that there are vaccines and treatments to combat it.
Additional reporting by James Shotter in Jerusalem