A committee of the World Health Organization’s (WHO) Strategic and Technical Advisory Group on Infectious Hazards with Pandemic and Epidemic Potential (STAG-IH) was to meet yesterday to review the sudden explosion of monkeypox cases across the globe. 

More than 130 cases of known (80) or suspected (50) monkeypox cases are under investigation spanning 12 non-African countries: Belgium, France, Germany, Italy, the Netherlands, Portugal, Spain, Sweden and the United Kingdom, as well as Canada, Australia and the United States. 

Only one of these confirmed cases has been linked to travel from Nigeria, a country known to have endemic monkeypox. The man, who developed a rash on April 29, flew to the UK on May 4 and informed authorities of his symptoms. He was immediately isolated, and the blisters were sampled and sent for PCR testing at Porton Down science park, which confirmed the infection on May 7.

What has public health officials concerned is that cases are geographically dispersed across Europe, the Atlantic and as far as Oceania. They suspect that the disease has been spreading undetected for some time. These developments shouldn’t come as a surprise, as all social restrictions against COVID have been lifted and international flights have begun carrying hundreds of millions of passengers this year. Meanwhile, public health efforts have been decimated by two years of non-stop waves of infections. 

The WHO regional director for Europe, Dr. Hans Kluge, noted, “Monkeypox is usually a self-limiting illness, and most of those infected will recover within a few weeks without treatment. However, the disease can be more severe, especially in young children, pregnant women, and individuals who are immunocompromised.” It remains to be seen if previous infection to SARS-CoV-2 will predispose people to complications from monkeypox.

Genomic sequencing of the current strain of the monkeypox suggests it is the less severe West Africa clade (genomic family), with a case fatality rate of less than one percent, or the mild version. The clade from the Congo basin carries a ten percent fatality rate. However, n article published in Nature yesterday stated, “Exactly how much the strain causing the current outbreaks differs from the one in western Africa—and whether the viruses popping up in various countries are linked to one another—remains unknown.”

Dr. Raina MacIntyre, infectious disease epidemiologist and monkeypox expert at the University of New South Wales in Australia, said that answers to these questions are critical in explaining if the sudden rise in cases is a byproduct of a mutation that allows the monkeypox virus to transit more efficiently than the ancestral versions. It would also answer if the outbreaks can be traced back to a single origin.

The deputy director of the CDC’s division of high consequences pathogens and pathology, Jennifer McQuiston, said earlier in the week about the monkeypox epidemic, “[While] we’re seeing this expansion of confirmed and suspect cases globally, we have a sense that no one has their arms around this to know how large and expansive it might be. And given how much travel there is between the United States and Europe, I am very confident we’re going to see cases in the United States.”

Currently six people are being monitored who were close contacts of the man who flew back to the UK from Nigeria. Another man in Massachusetts with confirmed monkeypox had been in Quebec, where several cases have been confirmed. Another man currently at Bellevue Hospital is being investigated for infection, according to the New York City Health Department.

The disparate cases imply undetected spread has been taking place. Usually, the disease manifests in lesions that begin on the face and spread to the other parts of the body, forming into blisters that burst, then scar, leading to the pathognomonic (disease-specific) skin lesions. The consequence here is that monkeypox does not go unnoticed to the infected person or others. If the monkeypox virus is spreading asymptomatically, that would have significant public health ramifications.

Health authorities have also been perplexed by the fact that most of the cases have been among young and middle-aged men, many of whom are gay or bisexual and have sex with men (GBMSM). MacIntyre told Nature she suspects “that the virus was coincidentally introduced into a GBMSM community, and the virus has continued circulating there.” Such reports will certainly lead to stigmatizing this community once more, as with HIV.

However, Dr. Kluge warned, “As we enter the summer season in the European region, with mass gatherings, festivals and parties, I am concerned that transmission could accelerate, as the cases currently being detected are among those engaging in sexual activity, and the symptoms are unfamiliar to many.”

Vaccines against smallpox offer 85 percent protection against monkeypox, as the variola virus is very similar. However, smallpox vaccination ended in 1980 when the disease was eradicated, meaning that those younger than 45 are unvaccinated and thus fully susceptible to the monkeypox virus. This of course includes all children, who are not less severely infected, as they have been so far with SARS-CoV-2 virus. Also, decades of waning immunity to smallpox have likely made the elderly vulnerable again.

Public health authorities are attempting to assure the public that ample supplies of smallpox vaccines, including antiviral treatments against monkeypox virus, are available. But instead of employing these in mass vaccination campaigns, healthcare workers would utilize a method called “ring vaccination,” where close contacts of infected patients would receive these treatments. However, this implies a program of contact tracing would be necessary to detail every chain of transmission.

Countries are beginning to secure contracts with the maker of the smallpox vaccine, Bavarian Nordic, a Danish company. On Wednesday, the company said BARDA (the US Department of Health and Human Services’ Biomedical Advanced Research and Development Authority for the Strategic National Stockpile) had exercised a $119 million option to manufacture the freeze-dried doses of Jynneos (smallpox and monkeypox vaccine live, non-replicating) in 2023 and 2024 to replace the current stock of bulk vaccine, according to Fierce Pharma.

They also said, “U.S. company Emergent BioSolutions also has an FDA-approved smallpox vaccine, ACAM2000, which isn’t available in the EU. Emergent nabbed an award worth up to $2 billion to deliver ACAM2000 to the Strategic National Stockpile over 10 years.”