Some countries have large stockpiles of the smallpox vaccine as part of pandemic preparedness, including the United States
The UK Health Security Agency (UKHSA) has confirmed 20 cases of monkeypox in the UK, with nine other countries outside of Central and West Africa also reporting outbreaks.
The disease, which was first found in monkeys, can be transmitted from person to person through close physical contact, including sexual intercourse.
A form of smallpox vaccin Why is the jab being used?
While there is not a specific vaccine for monkeypox, a smallpox vaccine does offer some protection, according to the UKHSA. The two viruses are closely related.
Data show that vaccines that were used to eradicate smallpox are up to 85 per cent effective against monkeypox, according to the World Health Organisation.
“Those who have required the vaccine have been offered it,” a UKHSA spokesperson said, without disclosing specifics on how many people have been vaccinated so far.
Smallpox vaccine immunity lasts for three to five years in people who are vaccinated for the first time.
People who are re-vaccinated may have longer protection lasting for about 10 years.
Some countries have large stockpiles of the smallpox vaccine as part of pandemic preparedness, including the United States.
On Thursday, Copenhagen-based drugmaker Bavarian Nordic said it had secured a contract with an undisclosed European country to supply its smallpox vaccine, Imvanex, in response to the monkeypox outbreak.
When did the smallpox vaccine stop?
Smallpox was a highly infectious and deadly disease which killed around 300 million people in the 20th century alone.
Compulsory infant vaccination was introduced in England by the 1853 Vaccination Act, with fines for non-compliance and imprisonment for non-payment following in 1871.