The WHO said Friday it had for the first time prequalified an mpox vaccine -- a move expected to speed up access to the jabs to fight an epidemic raging in Africa.
The announcement came on the heels of the arrival of the first MVA-BN vaccines to the Democratic Republic of Congo, the epicentre of the epidemic.
"This first prequalification of a vaccine against mpox is an important step in our fight against the disease, both in the context of the current outbreaks in Africa, and in future," WHO chief Tedros Adhanom Ghebreyesus said in a statement.
"We now need urgent scale up in procurement, donations and rollout to ensure equitable access to vaccines where they are needed most... to prevent infections, stop transmission and save lives."
WHO's prequalification listing is used to evaluate the quality, safety and efficacy of medical products like vaccines, paving the way for the United Nations and other international agencies to procure them.
The list is also used by lower-income countries without the means to carry out their evaluations to fast-track procurement approvals.
"The WHO prequalification of the MVA-BN vaccine will help accelerate ongoing procurement of the mpox vaccines by governments and international agencies... on the frontlines of the ongoing emergency in Africa and beyond," said Yukiko Nakatani, WHO's assistant chief in charge of access to medicines and health products.
Mpox, previously known as monkeypox, is caused by a virus transmitted to humans by infected animals but can also be passed from human to human through close physical contact.
It causes fever, muscular aches and large boil-like skin lesions, and can in some cases be deadly.
The WHO declared an international emergency over mpox last month, concerned by the surge in cases of the new Clade 1b strain in the DRC that spread to nearby countries.
DRC has recorded nearly 22,000 cases and 716 deaths linked to the virus since January.
So far, some 200,000 vaccine doses have been delivered to the DRC by the European Union, along with about 50,000 from the United States.
Safe and effective
WHO said it had based its prequalification assessment on information submitted by the manufacturer of the MVA-BN vaccine, Bavarian Nordic A/S, and review by the European Medicines Agency.
"Good safety profile and vaccine performance has been consistently demonstrated in clinical studies, as well as in real-world use," it said.
According to the prequalification, the vaccine can be administered to people over the age of 18 as a two-dose injection given four weeks apart.
With a majority of mpox cases and deaths in the DRC in children, WHO stressed that the vaccine could be used "off-label" in infants, children and adolescents, as well as in pregnant and immunocompromised people.
"This means vaccine use is recommended in outbreak settings where the benefits of vaccination outweigh the potential risks," WHO said.
The agency also recommends single-dose use in outbreak settings where supply of the vaccine is constrained, although it stressed that more data was needed on vaccine safety and effectiveness in such circumstances.
The currently available data, it said, shows that a single dose of the MVA-BN vaccine given before exposure has an estimated 76 percent effectiveness in protecting against mpox, while two doses are estimated to be 82 percent effective.
