An unusual wave of monkeypox cases in non-endemic regions has raised the possibility of another global health crisis even as COVID-19 persists. But two groups of biopharma experts argue monkeypox likely won’t escalate into another pandemic that humans struggle to contain.
The reason? While COVID was caused by a novel coronavirus, the world already has vaccines and therapeutics against the monkeypox virus, Berenberg analyst Zhiqiang Shu, Ph.D., and GlobalData analyst Emily Martyn said in their separate analyses.
Existing countermeasures suggest “the potential spreading can be effectively halted without implementing draconian containment measures that may hurt the global economy,” Shu wrote in a note on Monday.
As of Saturday, the World Health Organization has recorded 92 lab-confirmed monkeypox cases and 28 suspected cases in non-endemic regions across U.S., Canada, Australia and several countries in Europe. In those territories, at least two vaccines and two antivirals have been approved against monkeypox or its close relative smallpox, which was declared eradicated in 1980.
Bavarian Nordic has a live attenuated vaccine, called Jynneos in the U.S., for both smallpox and monkeypox. The vaccine carries the brand name Imvanex in Europe. Emergent BioSolutions developed smallpox shot ACAM2000. Though not commercially available, the two shots are included in the U.S. government’s strategic stockpile.
A smallpox vaccine could also protect against monkeypox because of the similarities between the two viruses, according to the CDC. Past data from Africa suggests that a smallpox vaccine can be at least 85% effective in preventing monkeypox, the CDC says.
As for whether mRNA vaccine technology could be adopted against monkeypox, Shu said it remains to be seen whether an mRNA shot can encode for a large protein that the virus uses to enter a human cell. The tech made a major debut during COVID, leading to vaccines that saved many lives.
In therapeutics, Emergent is in the process of buying FDA-approved smallpox oral antiviral Tembexa from Chimerix, and Siga Technologies’ Tpoxx is produced both in oral and intravenous formulations for smallpox treatment.
Availability of existing products is just one aspect that gives Shu confidence in monkeypox’s limited impact.
As an RNA virus, the SARS-CoV-2 coronavirus behind COVID is prone to mutations. The currently dominant omicron variant has rendered existing vaccines and antibody drugs less effective. But monkeypox is a DNA virus, which means it’s less likely to mutate, at least not as frequently as the coronavirus, Shu wrote.
New sequencing data of an infected male patient in Portugal—which has reported 23 cases as of Friday—showed the current virus is very closely related to the one involved in a previous outbreak in 2018 and 2019 after exportation from Nigeria to several countries. Shu also pointed out that the current virus shows only “minor genetic variations” compared with the first strains collected in the 1970s.
Besides, monkeypox appears much less contagious and typically causes flu-like self-limited disease at least for now. Before the latest outbreak, monkeypox was believed to be mainly transmitted from animal to human but seldom among humans, which “suggests effective containment is likely,” Shu said.
During the largest U.S. outbreak in 2003, none of the 47 cases from six states were caused by human-to-human transmission, Shu noted. Historically, human-to-human transmission only happened in about 28% of cases during very close contact to the infected person such as via body fluids, GlobalData’s Martyn said.
Scientists have yet to pinpoint exactly how people got infected in the ongoing outbreak. As the WHO noted, it’s atypical that cases don’t have travel history to an endemic area emerge in multiple countries. The current hypothesis points to sexual contact. If this turns out to be the case, monkeypox will still be less contagious than airborne viruses like COVID-19 and the flu, Shu said.
“Additionally, national and international health services can utilize their existing COVID-19 systems to work together to address and control this issue quickly and effectively,” Martyn said.