These two latest cases are only the fifth and sixth ever to be found in the UK. A small number of healthcare workers who were treating the patients in England have been given the jab. The patients are reportedly from North Wales but were treated in Liverpool.
Dutch drug company Bavarian Nordic worked alongside UK health officials to deliver its smallpox vaccine IMVANEX.
This jab, while for a different virus, has also been approved for monkeypox by the US FDA as the rare virus is closely related to smallpox.
The same jab was previously used to immunise NHS staff in 2018 following an outbreak of monkeypox.
A nurse said she became infected after changing the bedsheets of a patient.
Paul Chaplin, President and CEO of the pharmaceutical company, said: “We are pleased to assist Public Health England rapidly in such an emergency situation.
“Vaccination is a critical measure to prevent and control the spread of diseases globally.
“Governments have an essential role in preparing for outbreaks by stockpiling vaccines and treatments so that they are readily available in events like this.”
Public Health England said the risk to the public was still considered “low”.
READ MORE: How is monkeypox transmitted?
“The index case was acquired overseas, and the two cases are members of the same household.
“Both cases were admitted to a hospital in England, where one currently remains.
“Monitoring and follow-up of the cases and their close contacts are undertaken as part of normal practice, and the risk to the general public is very low.”
Richard Firth Consultant in Health Protection at Public Health Wales, said: “Confirmed cases of monkeypox are a rare event in the UK, and the risk to the general public is very low.
“We have worked with multi-agency colleagues, following tried and tested protocols and procedures, and identified all close contacts.
“Actions have been put in place to minimise the likelihood of further infection.
“Monkeypox is a rare disease caused by the monkeypox virus and has been reported mainly in central and West African countries.”
Monkeypox is zoonosis – meaning it is transmitted from animals to humans.
It often starts with a rash before red spots appear and spread across the body, turning into red bumps filled with fluid.
These are often accompanied by flu-like symptoms such as high temperature, muscle aches and swollen glands.
Cases are often found close to tropical rainforests where there are animals that carry the virus.