Geneva, Switzerland - The mpox outbreak is not another Covid-19, the World Health Organization said Tuesday, because much is already known about the virus and the means to control it.

While more research is needed on the Clade 1b strain which triggered the UN agency into declaring an international health emergency, the spread of mpox can be reined in, the WHO's European director Hans Kluge said.

"Mpox is not the new Covid," he said.

"We know how to control mpox. And, in the European region, the steps needed to eliminate its transmission altogether," he told a media briefing in Geneva, via video link.

In July 2022, the WHO declared an emergency over the international outbreak of the less severe Clade 2b strain of mpox, which mostly affected men who have sex with men. The alarm was lifted in May 2023.

"We controlled mpox in Europe thanks to the direct engagement with the most affected communities," said Kluge.

Robust surveillance, investigating case contacts, behavior changes in the affected communities, and vaccination all contributed to controlling the outbreak, he said.

Kluge said the risk to the general population was low.

"Are we going to go in lockdown in the WHO European region, [as if] it's another Covid-19? The answer is clearly: 'no,'" he said.

Clade 1b is spreading mainly through sexual transmission among adults.

Kluge said it was also possible that someone in the acute phase of mpox infection, especially with blisters in the mouth, may transmit the virus to close contact by droplets, in circumstances such as in the home or in hospitals.

"The modes of transmission are still a bit unclear. More research is required," he said.

WHO spokesman Tarik Jasarevic said the agency was not recommending the use of masks.

"We are not recommending mass vaccination. We are recommending to use vaccines in outbreak settings for the groups who are most at risk," he added.

The WHO declared an international health emergency on August 14, concerned by the rise in cases of Clade 1b in the DR Congo and its spread to nearby countries.

Vaccines can also be used preventatively in people likely to be exposed to the virus.

Jasarevic said results from effectiveness studies indicated that a good level of protection was provided against mpox following vaccination.

However, it takes several weeks to develop immunity after being vaccinated.