The World Health Organization on Wednesday appealed for vigilance to ensure Monkeypox does not spread among more vulnerable groups, such as children.

The WHO called for "intense" efforts to combat the virus, as well as broad data collection and sharing on how well vaccines work against it.

Since early May, experts have detected an increase in Monkeypox cases outside of the West and Central African countries where the disease has long been endemic. The majority of the new cases have occurred in Western Europe.

"I am concerned about sustained transmission because it would suggest that the virus is establishing itself and it could move into high-risk groups including children, the immunocompromised and pregnant women," WHO chief Tedros Adhanom Ghebreyesus told reporters. "We are starting to see this, with several children already infected." There are two cases aged under 18 in Britain.

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Soumya Swaminathan, WHO chief scientist, has called for "very careful studies of the vaccine in different population groups... so that we get broadly applicable data, and also to ensure that children, pregnant women, and immunosuppressed are considered for inclusion in these trials."

As of June 22 of this year, the WHO had received reports of 3,413 laboratory-confirmed cases and one death from 50 countries.

WHO Emergency Director Michael Ryan stated that countries with vaccine stockpiles have expressed willingness to share them.

However, they were mostly only approved for use against Monkeypox's far more severe cousin smallpox, which is also caused by an orthopoxvirus and is the only disease that has been successfully eradicated through vaccination.

"It's really important as we encourage the sharing of these products that we also collect the necessary clinical efficacy data," said Ryan.

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