MPOX quickly spreads: the researchers are driving these questions ahead

nature.com/lw767/magazine-assets/d41586-02793-9/d41586-02793-9_27619832.jpg?as=Webp 767W, https://media.nature.com/lw319/magazine-assets/d41586-02793-9/d41586-02793-9_27619832.jpg?as=webp 319W "SIZES =" (Max-Width) 319PX, (Min-Width: 1023px) 100VW, 767PX ">

as the World Health Organization (who) at the beginning of this month explained a public health emergency about MPOX , it was because a worrying form of the virus caused this disease had spread in several African countries where it had never been seen before. Since then, two people have been infected when traveling to Africa - one from Sweden and one from Thailand - with this Virus of Type Clade 1b and brought it back to their countries.

Although researchers have known about the current outbreak since the end of last year, the need for answers is now more urgent than ever. The Democratic Republic of Congo (DRC) in Central Africa has been struggling with the Clade-i virus-a group to which IB has been part of the IB for decades. So far, Clade-I infections usually have been created when a person has contact with wild animals and the outbreaks are stalling.

clade ib seems to be different and mainly spreads through human contact, also through sex . In the DRC alone, almost 18,000 cases of MPOX - many of them in children - and at least 600 deaths were reported.

How does this emergency compared to the one who was explained in 2022 as MPOX cases worldwide? How does this virus behave compared to the version that triggered this outbreak, a kind of called Clade II? And will Africa be able to get this problem under control? Nature talks to researchers about the information they collect in a hurry.

is Clade IB fatal than the other types of virus?

It is difficult to determine, says Jason Kindrachuk, a virologist at the University of Manitoba in Winnipeg, Canada. There are currently two simultaneous outbreaks in the DRC. The Clade-I virus, which has been endemic in forested regions of DRC for decades, circulates in rural areas where people get it from animals. This clade was renamed IA after the discovery of Clade IB. Animal experiments suggest that Clade I is fatal than Clade II 1 , but Kindrachuk says that it is difficult, too speculate what that means for humans.

Even if not fatal, MPOX can trigger fever, pain and painful skin lesions filled with liquid.

Although many reports say that 10% of Clade I infections are fatal in humans, the infectious diseases specialist Laurens Liesenburghs at the Institute of Tropical Medicine in Antwerp, Belgium doubts that this number is precisely. Even the latest estimate of the WHO of a mortality rate of 3.5% in people with MPOX in the DRC could be high.

There are many reasons why mortality estimates could be unreliable, says Liesenborghs. On the one hand, the monitoring data only captures the most difficult cases. Many people who are less sick may not look for treatment in hospitals or at doctors, so that their infections are not reported.

Another factor that can falsify the mortality rate is a secondary health disorder. For example, people with HIV-who make a significant proportion of the population in many African countries-die to MPOX with a rate of twice as high as people who do not have an impaired immune system, especially if their HIV is left untreated 2 . The high death rate in children under 5 years could be partially due to malnutrition, which often occurs in rural parts of the DRC in children, says Liesenborghs.

is Clade IB more contagious than other types?

The Clade 1b Virus has attracted special attention because epidemiological data indicate that it is more easily transmitted between people than earlier tribes, including sexual activity, while Clade IA mainly comes from animals. An analysis that was published last week before the peer review on the Preprint server Medrxiv 3 The genome of Clade IB contains genetic mutations that apparently have been induced by the human immune system and indicate that it has been in humans for some time. Clade ia genome have less of these mutations.

But Liesenborghs says that the mutations and clads may not be the most important factor to understand how the monkey) virus is spreading. Although it is useful to distinguish IA from IB, he says, the severity and transferability of the disease could be stronger by the region in which the virus circulates and the people living there are influenced. For example, Clade IA seems to be more common in sparsely populated rural regions, in which it is less likely that it is widespread. Clade IB appears in densely populated areas and spreads faster.

Jean Nachega, an infectious doctor at the University of Pittsburgh in Pennsylvania, says that scientists do not understand many aspects of the transfer of MPOX-they have not even found out which animal serves as a reservoir for the virus in nature, although rodents can wear it. "We have to be very modest," says Nanceega.

How effective are vaccines against the Clade I virus?

As during the Covid 19 pandemic, health experts look at vaccines to curb the current MPOX outbreak. Although there are no vaccines specially developed against the monkey quantity virus, there are vaccines that have contributed to warding off a related virus-the one that causes smallpox. Two currently exist. Jynneos, manufactured by Bavarian Nordic in Hellerup, Denmark, contains a kind of smallpox virus that cannot multiply but can trigger an immune response. LC16M8, manufactured by KM Biologics in Kumamoto, Japan, contains a living - but weakened - version of another Pox virus tribe.

However, it is unclear how effective these smallpox vaccines are generally against MPOX. Dimie Ogoina, an infectious disease specialist at Niger Delta University in Wilberforce Island, Nigeria, indicates that vaccines were only tested against the Clade II virus in European and American populations, since these vaccinations . And the recipients were mainly young, healthy men who have sex with men, the population who advanced this outbreak. A study in the United States showed that a dose of Jynneos was exposed to a risk that was 80% effective, while two doses were 82% effective 4 ; The WHO recommends receiving both vaccinations.

People in Africa who are infected with the Clade-Och or -1B virus-especially children and people with impaired immune system-could react differently, although a study in the DRC found that the Jynneos vaccine was generally able to form antibodies against MPOX for around 1,000 health personnel.

But researchers try to fill some data gaps. A team in the DRC will soon start a clinical study with Jynneos to people who have come into close contact with the monkey -compartment virus - but have not shown any symptoms - to see whether it can prevent future infection or improve the results.

will the vaccines help to contain the latest outbreak?

So far, MPOX vaccines were largely not available in Africa, but several wealthy countries have promised to donate doses to the DRC and other affected African countries. The United States offered 50,000 Jynneos doses from their national stock, and the European Union has ordered 175,000, with individual member countries have promised additional doses and Bavarian Nordic added another 40,000. Japan offered 3.5 million doses of LC16M8 (which only requires a vaccination instead of two).

So far, none of these doses have arrived, says Espoir Bwenge Malembaka, an epidemiologist at the Catholic University of Bukavu in the DRC. Low and medium -sized income countries that are dependent on vaccine donations can only be preserved when the WHO has confirmed that the vaccinations are safe and effective. So far, the WHO has not given a green light. It evaluates additional data that she has received from vaccine manufacturers, which prevents the senders from sending the vaccines.

Even if the vaccines arrive, says Bwenge Malembaka, "it's really a drop on the hot stone". The African Centres for Disease Control and Prevention in Addis Ababa, Ethiopia, estimates that 10 million cans are needed to curb the outbreak.

bwenge Malembaka says that the government has made it difficult for the government to create a distribution plan. "I don't know how to tackle this problem," he says. Bwenge Malembaka suspects that children are likely to receive cans first because they are particularly susceptible to Clade I, but the authorities have not yet decided which regions they should address. It is also unclear how the government would prioritize other endangered population groups, such as: B. sex workers who were affected by Clade IB. Your job is criminalized in the DRC, so that you may not be able to report for treatment.

researchers regret that public health organizations did not provide vaccines and other resources at an early stage than the Clade-I outbreak was identified, especially in view of the teachings from the global MPOX outbreak of 2022. "The opportunity existed a few months ago, but the resources were not available," says Liesenborths. "Now it will be more difficult to cope with this outbreak, and the endangered population is much wider."