Dr Jake Dunning
Head of Emerging Infections and Zoonoses, Public Health England
Within one week in 2018, the UK had two unrelated cases of monkeypox in individuals returning from Nigeria. There was also transmission to a third person – a healthcare worker – the first occurrence of person-to-person transmission recorded outside of Africa.
Monkeypox is a rare viral infection, from the same family of viruses as smallpox. The first human case was recorded in 1970 in the Democratic Republic of the Congo (DRC). Since then, the infection has been reported in many central and west African countries, with most cases from remote parts of the DRC and Nigeria.
In 2003, an outbreak was recorded in the USA following importation of rodents from Africa. All the human infections followed contact with an infected pet. Fortunately, all patients recovered.
An outbreak anywhere in the world can have far-reaching implications for the UK, even if we have had very few cases. While it can be difficult to predict what is going to emerge as the latest threat, Public Health England has robust epidemic intelligence systems for detecting and assessing the risk to the UK from infectious diseases either at home or abroad.
Our study will provide additional scientific evidence to support the public health response of offering the vaccine during the recent UK monkeypox outbreaks.
The vaccine
First-generation smallpox vaccines were initially produced in the late fifties, during the global smallpox eradication programme. Second-generation vaccines differed from the first as they were made using animal cells.
To reduce the complications experienced with the first- and second-generation vaccines, a third generation of attenuated vaccines were developed at the end of the global smallpox eradication programme. Attenuated vaccines use a weakened form of a virus, to provoke as strong and long-lasting an immune response as possible. It cannot, however, spread or cause smallpox or monkeypox infection.
As part of the UK public health response, contacts of confirmed monkeypox cases were given a pre-exposure prophylaxis for specialist healthcare workers. In the UK, this is the first time that a third-generation smallpox vaccine has been used as a public-health response intervention during a monkeypox outbreak.
The study
Studying this outbreak provides the unique opportunity to quantify and characterise antibody responses to the third-generation vaccine. So far, studies assessing immunised responses to monkey pox happen in the lab, whereas this is the first, real-world population study.
In addition, the study intends to demonstrate that vaccine-induced antibodies neutralise the specific monkeypox viruses involved in the UK outbreak.
All participants are healthcare workers who received the vaccine, or pre-exposure or post-exposure prophylaxis, during the 2018 cluster of cases. As of 12 October 2018, at least 59 healthcare workers have received post-exposure vaccine and at least 57 healthcare workers have received pre-exposure vaccine.
“Our study will provide additional scientific evidence to support the public health response of offering the vaccine during the recent UK monkeypox outbreaks.
“I hope that the results of our study provide reassurance to other countries that are considering adopting the vaccine for outbreak-associated vaccination.”
