Data shows that vaccines that were used to eradicate smallpox are up to 85 percent effective against monkeypox, according to the World Health Organization (WHO).

There isn't a specific vaccine for monkeypox, but a smallpox vaccine does offer some protection.

Reuters has reported that the UK has already offered smallpox vaccines to some healthcare workers and others who may have been exposed. Some countries have large stockpiles of the smallpox vaccine as part of pandemic preparedness.

The WHO said it expects to identify more cases of monkeypox as it expands surveillance in countries where the viral disease is not typically found.

As of Saturday, 92 confirmed cases and 28 suspected cases of monkeypox had been reported from 12 member states that are not endemic for the virus, the UN agency said, adding it will provide further guidance and recommendations in coming days for countries on how to mitigate the spread of monkeypox.

What about the current cases?

Many of the current cases have been identified at sexual health clinics.

Early genomic sequencing of a handful of the cases in Europe has suggested a similarity with the strain that spread in a limited fashion in Britain, Israel and Singapore in 2018.

David Heymann, a WHO official and an infectious disease specialist, told Reuters that it was "biologically plausible" the virus had been circulating outside of the countries where it is endemic, but had not led to major outbreaks as a result of COVID-19 lockdowns, social distancing and travel restrictions.

How dangerous is it?

The risk to the general public is low at this time, a senior U.S. public health official said on Friday.

Monkeypox is a virus that can cause symptoms including fever and aches, and presents with a distinctive bumpy rash.

It is related to smallpox, but is usually milder. It is spread by close physical contact with someone who has an active rash, so it can be relatively easily contained through such measures as self-isolation and hygiene.

Heymann said that the monkeypox outbreak did not resemble the early days of the COVID-19 pandemic because it does not transmit as easily.

"There are vaccines available, but the most important message is, you can protect yourself," he added.

"COVID is spread by respiratory route and is highly infectious. This doesn't appear to be the case with the monkeypox," said Dr Martin Hirsch of Massachusetts General Hospital.

Why are health experts concerned?

The recent outbreaks reported are atypical, according to the WHO, as they are occurring in countries where the virus does not regularly circulate. Scientists are seeking to understand the origin of the current cases and whether anything about the virus has changed.

Most of the cases reported so far have been detected in the UK, Spain and Portugal. There have also been cases in Canada and Australia, and a single case of monkeypox was confirmed in Boston, with public health officials saying more cases are likely to turn up in the United States.

WHO officials have expressed concern that more infections could arise as people gather for festivals, parties and holidays during the coming summer months in Europe and elsewhere.

(With input from agencies)