MPOX, the viral disease formerly known as monkeypox, is once again a global threat. On Wednesday afternoon, the World Health Organization declared a Public Health Emergency of International Concern (PHEIC) for MPOX, citing a resurgence of cases across Africa and the emergence of new, more deadly variants of the virus.
Mpox is caused by a virus closely related to the now extinct smallpox virus. It has long been considered a zoonotic disease, spreading primarily from animals (rodents, not monkeys) to humans. However, this changed in early 2022 when the virus began causing widespread human-to-human outbreaks outside of Africa. These outbreaks have spread around the world, with over 90,000 documented cases in over 100 countries. The WHO issued its first PHEIC on Mpox in July 2022, which was also the first declaration since the arrival of COVID-19.
Mpox infections usually cause flu-like symptoms, headaches, and a characteristic bumpy rash or lesions that appear all over the body, with symptoms appearing within 21 days of infection. People can spread the infection to others several days before they feel unwell, and they remain contagious until the rash has completely healed. The rash can take 2-4 weeks to heal completely. The virus could theoretically be spread by any direct contact. However, in the 2022 outbreak, it was primarily transmitted sexually among gay and bisexual men. Fortunately, the strain that spread belongs to a less lethal virus lineage (clade II), and only about 150 deaths were reported in 2022.
Scientists had already developed a vaccine for MPOX before these outbreaks (due to its similarity to smallpox). Vaccination and awareness campaigns in high-risk areas have reduced the number of MPOX cases since 2022, and the first WHO PHEIC on MPOX is scheduled to end in May 2023. However, experts are concerned that the virus could cause further major outbreaks or mutate further to become more dangerous, and those fears are real.
According to the Associated Press, there have been more than 14,000 suspected or confirmed cases and 524 deaths linked to MPOX this year. These cases and deaths have been identified in 13 countries, with most concentrated in the Democratic Republic of Congo. These outbreaks are linked to an established lineage of the virus (clade I), but a new variant (clade Ib) that is more deadly than the strain that emerged globally in 2022 appears to be circulating widely now, with the mortality rate hovering around 3-4%. As in 2022, early outbreaks appear to have spread primarily through sexual contact, but doctors have recently reported a marked increase in cases affecting younger children, health care workers, and households. This raises the real possibility that the virus may also be easily spread through other forms of direct contact.
Last week, the Africa Centers for Disease Control and Prevention declared the outbreak a public emergency. But while so far the danger has been mostly confined to Africa, the WHO declaration indicates that other parts of the world are not necessarily safe from MPOX.
“The emergence of a new MPOX lineage, its rapid spread in eastern DRC and reported cases in several neighbouring countries is deeply worrying. This, along with other MPOX lineage outbreaks in the DRC and other African countries, clearly requires a coordinated international response to stop these outbreaks and save lives,” WHO Director-General Tedros Adhanom Ghebreyesus said in announcing the decision.
While U.S. supplies of the most widely used polio vaccine (Jynneos) have recently been replenished, the same is not true for the countries currently most affected by these outbreaks, and experts have warned that initial vaccine supplies will likely fall far short of the 3 million doses planned to be provided to Africa by the end of the year.
The WHO has already taken steps to accelerate emergency approval of a vaccine in low-income countries that do not have an approved vaccine, and has disbursed $1.45 million from its emergency reserve fund to deal with the crisis. The WHO is also working to coordinate vaccine donations from other countries and pharmaceutical companies. But these measures alone are clearly not enough. The WHO estimates that at least $15 million will be needed immediately to fund surveillance, preparedness, and response activities, and plans to appeal to donors for more funding.