The World Health Organisation urged pharmaceutical firms to ramp up vaccine production and China said it would screen travellers for the disease after the first cases of the more deadly strain to be recorded outside Africa were announced in Sweden and Pakistan.

France’s Prime Minister Gabriel Attal said his country was on the “highest alert” and would implement “new recommendations” for travellers to risk areas.

Mpox is caused by a virus transmitted to humans by animals but can also spread human-to-human through close physical contact.

It causes fever, muscular aches and large boil-like skin lesions.

The WHO on Wednesday declared the rapid spread of the new Clade 1b strain an international public health emergency — the agency’s highest alert.

This follows the spread of the more deadly mpox from Democratic Republic of Congo (DRC) to other African countries.

READ ALSO: Sweden reports first case of deadly mpox strain outside Africa

“We do need the manufacturers to really scale up so that we’ve got access to many, many more vaccines,” WHO spokeswoman Margaret Harris told reporters.

The WHO is asking countries with vaccine stockpiles to donate them to countries with outbreaks.

Harris said mpox was “particularly dangerous for those with a weak immune system, so people who maybe have HIV or are malnourished”, and was also dangerous for small children.

The United States has said it will donate 50,000 doses of an mpox vaccine to DRC and Attal said France would also send vaccines to risk countries.

Danish drugmaker Bavarian Nordic said Thursday it would be ready to make up to 10 million doses of its mpox vaccine by 2025 but that it needed contracts to start production.

The Stockholm-based European Centre for Disease Prevention and Control (ECDC) said the overall risk in Europe was “low”. But it warned that “effective surveillance, laboratory testing, epidemiological investigation and contact tracing capacities will be vital to detecting cases.”

“Due to the close links between Europe and Africa, we must be prepared for more imported clade I cases,” ECDC director Pamela Rendi-Wagner said in a statement.

Hundreds killed in DRC

The virus has swept across DRC, killing 548 people so far this year, the government said Thursday.

Nigeria has recorded 39 mpox cases this year, but no deaths, according to its health authorities. Previously unaffected countries such as Burundi, Kenya, Rwanda and Uganda have reported outbreaks, according to the Africa Centres for Disease Control and Prevention.

Sweden’s Public Health Agency announced Thursday it had registered a case of Clade 1b.

The patient was infected during a visit to “the part of Africa where there is a major outbreak of mpox Clade 1”, epidemiologist Magnus Gisslen said in a statement.

The mpox strain in the Pakistan case was not immediately known, the country’s health ministry said in a statement.

It said the patient, a 34-year-old man, had “come from a Gulf country”.

China announced it would begin screening people and goods entering the country for mpox over the next six months.

People arriving from countries where outbreaks have occurred, who have been in contact with mpox cases or display symptoms should “declare to customs when entering the country”, China’s customs administration said.

Vehicles, containers and items from areas with mpox cases should be sanitised, it added in a statement.

Vaccination drive

Mpox has two subtypes: the more virulent and deadlier Clade 1, endemic in the Congo Basin in central Africa; and Clade 2, endemic in West Africa.

A worldwide outbreak beginning in 2022 involving the Clade 2b subclade caused some 140 deaths out of about 90,000 cases, mostly affecting gay and bisexual men.

France reported 107 cases of the milder mpox variant between January 1 and June 30 this year.

The WHO’s European regional office in Copenhagen said the Sweden case was “a clear reflection of the interconnectedness of our world”.

But it added: “Travel restrictions and border closures don’t work and should be avoided.”