The virus that is fuelling a surge in monkeypox cases globally may be mutating faster than anticipated as it spreads from person to person, a study has said, as authorities move to widen eligibility for vaccines to more groups seen to be at risk.
This evolution may explain why this strain of monkeypox appears to be more transmissible, researchers in Portugal wrote in a study published in Nature Medicine on Friday.
One of the study’s authors, João Paulo Gomes from Portugal’s National Institute of Health in Lisbon, said the world was grappling with an outbreak “caused by a virus that presents [many] more mutations than we could expect for this type of virus”.
“It was quite unexpected to find so many mutations in the 2022 monkeypox virus,” Gomes said. “In fact, considering the genome characteristics of this type of virus, no more than one or two mutations are likely to emerge each year.”
His team, in fact, observed about 50. Viruses such as monkeypox have tended to be relatively stable, and previous outbreaks tended to fizzle out whenever a case was detected in places where the disease was not endemic.
The World Health Organization has called a meeting of one of its advisory groups to determine whether the current monkeypox outbreak should be classed a public health emergency of international concern, the highest designation under international law. Covid-19, for example, is so classified. A decision could come as early as Friday.
The WHO does not have the authority to call the beginning of a pandemic, but began using the term for Covid in March 2020 to raise awareness of the disease.
Gomes’s research used metagenomics, which can help reconstruct genomic sequences in a time series. His institution published the first draft genome of the virus in this outbreak last month.
Globally, health authorities are closely tracking the evolution of the outbreak. New York City on Thursday became the latest area to expand vaccination; it opened eligibility to men who have sex with men who have had multiple or anonymous partners in the previous 14 days. It had previously offered the vaccine, designed for smallpox but shown to confer protection against monkeypox, to contacts of confirmed or probable cases.
The UK and parts of Canada have also similarly expanded use of the vaccine, which uses biotech Bavarian Nordic’s Imvanex. More than 3,000 cases have been reported to date, according to Our World in Data.
Monkeypox was first identified decades ago, although officials have pointed to a relative lack of literature on the subject. Some have said this was because of the disease’s previously limited area of spread.