What to know about the new mpox strain and global health emergency

The latest: Thailand's health authorities announced Thursday that test results had confirmed that a recently detected case of mpox in the country was indeed caused by the new strain.

• It is the first case of the new strain in Asia and the second outside of Africa.
• The Philippines' Department of Health announced Monday that it had detected the country's first case of mpox since last December. However, authorities are still waiting to determine the strain of the case, per Reuters.
• China's customs administration said last week that it would monitor people and goods entering the country for signs of the disease for the next six months, the state-run CGTN reported.

Flashback: The WHO issued its first declaration over mpox in July 2022, after the disease had spread to over 70 countries.

• Between 2022 and 2023, the outbreak caused more than 99,000 cases and more than 200 deaths, per estimates from the Centers for Disease Control and Prevention.
• It revoked the emergency status in May 2023, following a steep decline in cases as awareness of the disease increased and vaccines became more readily available.

What makes this mpox strain different?

There are two main strains of mpox, clade I and clade II, according to the CDC.

• The clade II strain is endemic to West Africa and fueled the mpox outbreak in 2022. However, cases from clade II are usually less severe and 99.9% of people who contract the strain survive, per the CDC.
• However, the new strain, clade I, is endemic to Central Africa and has proven more virulent and deadly than the clade II strain. Some previous outbreaks have killed up to 10% of those infected.
• Mpox is a zoonotic disease, meaning it can be spread from people to animals. Both strains spread via close contact with an infected person or animal or contact with contaminated materials.
• Both strains have similar symptoms, including flu-like symptoms and a rash can initially resemble pimples or blisters.

Zoom in: The previous outbreak of mpox primarily impacted men who have sex with men and their sexual partners.

• While the Democratic Republic of the Congo (DRC) has had intermittent cases of mpox for decades, most cases occurred in children in remote villages and were believed to be transmitted via rodents, according to Science.
• "For the first time sexual transmission in adults has been a major driver," the journal noted of the current outbreak in the DRC, adding that infection rates were especially high among female sex workers and their clients.

Where are new mpox cases happening?

The vast majority of current cases are in the DRC, where more than 14,000 cases — and 524 deaths — have been reported so far this year, WHO Director-General Tedros Adhanom Ghebreyesus said Wednesday.

• However, outbreaks have been reported in 15 countries so far.
• This includes four countries that had never previously reported mpox cases — Burundi, Kenya, Rwanda and Uganda, Tedros said.
• The U.S. Agency for International Development (USAID) announced earlier this month that it was committing roughly $424 million in humanitarian and health aid to combat the outbreak.

State of play: The European Centre for Disease Prevention and Control (ECDC) last week raised its risk assessment level for the new mpox strain, saying it is "highly likely" Europe will see new cases crop up.

• However, the ECDC noted that the likelihood of sustained transmission of the new strain in Europe remains low.

• Sweden's public health agency announced last Thursday that it had confirmed the first known case of the new mpox strain outside of Africa.
• The patient has received treatment in Stockholm after contracting the virus in a part of Africa where the new strain is currently circulating, the agency noted.

What does it mean for the U.S.?

The CDC has alerted doctors to be on the lookout for the new strain but has said that risk of it reaching the U.S. remains very low.

• "There are no known cases in the United States at this time," the Department of Health and Human Services said in a press release Wednesday, noting that the U.S. is well prepared detect and contain any potential future outbreaks.
• As of January 2023, roughly 1.2 million doses of the Jynneos vaccine had been administered in the U.S., per the CDC.

Are old mpox treatments effective on new strain?

The WHO's global health emergency will help improve access to vaccines for mpox, which health authorities still recommend for preventing infection.

• DRC officials in June authorized the emergency use of two vaccines: Jynneos, made by Bavarian Nordic, and LC16, from KM Biologics.
• HHS noted that the Jynneos vaccine is considered highly effective at preventing severe illness from mpox.

What they're saying: "Those who have already had clade II mpox or are fully vaccinated against mpox are expected to be protected against severe illness from clade I mpox," HHS added.

• However, health experts warn that there might not be enough vaccines to contain the current crisis, the New York Times reported.

Our thought bubble, from Axios' senior health care editor Adriel Bettelheim: There's debate over whether the mpox resurgence is mostly due to the virus mutating or because it's spreading to more groups via sexual transmission, or both.

• The real fear is the current outbreak could intensify if authorities can't get enough of the vaccines through what's a pretty fragile public health infrastructure.

Go deeper: WHO declares international mpox emergency

Editor's note: This story was updated with new developments.