Authorities in the Democratic of Congo have approved the use of two mpox vaccines to try to tackle an upsurge in cases and a dangerous new strain spreading in the country.

Congo has seen 20 000 cases and more than 1 000 deaths from mpox, mainly among children, since the start of last year.

The disease is a viral infection that spreads through close contact, causing flu-like symptoms and pus-filled lesions. Most cases are mild but it can kill.

This week, the World Health Organization (WHO) and scientists warned of a new, more deadly strain spreading in Congo's South Kivu province.

The regulator has issued an emergency use authorisation for both Bavarian Nordic's shot, Jynneos, and LC16, made by KM Biologics, according to documents and sources involved in the process.

Congo, one of the poorest countries in the world, saw the first human mpox case in 1970, but has never had access to vaccines or treatments to tackle the disease outside clinical trials.

Both tools were widely available in European countries and the United States in 2022 when an outbreak of a less severe strain of mpox spread globally.

In the latest outbreak in Congo, national and international regulatory barriers, a lack of funding, competing disease outbreaks and stigma have held back the response.

The chief executive of Gavi, the Vaccine Alliance, Sania Nishtar, told Reuters last week that her organisation was ready to use Covid-19 era protocols to facilitate donations of the vaccines from the United States and Japan once an approval was in place. A spokesperson for Bavarian Nordic on Wednesday confirmed the approval in Congo. KM Biologics said by email there was a potential supply of vaccine to Congo but it had no other information to share.

Although the Congo authorities have approved the vaccines, Gavi, which funds the purchase of vaccines for low-income countries that are unable to do so alone, cannot buy them without them being "pre-qualified" by the World Health Organization, a form of approval.

In the absence of the approval, Gavi is reliant on donated vaccines.

A WHO spokesperson said the agency is working with the vaccine manufacturers on an approval process. He urged countries to proceed with their own approvals as well as providing the WHO with more data to move the process forward.

Other challenges to tackling Congo's outbreak include stigma around the disease, which spreads through close contact, including sexual contact.

Funding is also an issue, Cris Kacita, who leads mpox operations nationally in Congo, told Reuters.

He said $84-million is needed to respond in the provinces most at risk, but only $8-million has been raised.