MPOX update: 16 August 2024
Earlier this week, the World Health Organisation (WHO) declared a public health emergency of international concern (PHEIC) in relation to the upsurge of mpox (monkeypox) in the Democratic Republic of Congo (DRC) and an increasing number of neighbouring countries, including Burundi, Kenya, Rwanda and Uganda.
The PHEIC was declared following the emergence of a new clade of mpox – clade 1b - that appears to be more easily transmitted than current clades. Clade 1b is a variant of mpox clade 1, which, on top of other existing clades of mpox, already impacts on the region.
Mpox was first detected in humans in 1970 in the DRC, and was seen to be largely transmitted through household contact. Mpox was rarely identified outside of this region.
In 2022, a new strain of mpox was identified that was largely transmitted through sexual contact. This clade – clade 2 – was primarily seen in men who have sex with men, and in parts of the world where mpox had previously not been identified. In some parts of the world, the outbreaks were contained following vaccination programmes. In other parts of the world, a failure to provide systematic vaccine programmes has led to on-going transmission.
In the UK, a widespread vaccination programme was undertaken, largely through sexual health clinics, and a recommendation was made in November 2023 – but not yet implemented – for a routine mpox vaccination programme to be implemented.
Research undertaken during and after the UK’s outbreak showed that:
A proportion of those who were exposed to and infected with mpox showed no visible symptoms, demonstrating that asymptomatic transmission is possible
Providing post-exposure (PEP) vaccination to individuals who had been exposed to mpox reduced symptoms and possible on-ward transmission
Partially (one dose) or fully (two doses) vaccinated individuals experienced far less severe symptoms of mpox if they were exposed to mpox and transmission occurred
The new clade, identified in the DRC, also appears to be being transmitted through sexual networks, and disproportionately impacting on key populations of people. A currently small number of cases, of the same clade, have been identified outside of the region – including in Sweden. No cases of clade 1b have yet been identified in the UK
It is essential that international focus and attention is given to the outbreak in and around the DRC. This must include immediate access to testing, vaccination and treatment. Outbreak measures should be undertaken with the upmost attention to anti-discrimination measures and human rights frameworks that do not stigmatise and harm already marginalised groups. Further action must be taken to accelerate vaccine access and production for lower-income countries, and WHO has already triggered processes for Emergency Use Listing for mpox vaccines.
Given the severity of the situation in DRC and its neighbours, a case should be made to shift stock-piled supplies of mpox vaccines to that region, as well as to consider programmes of vaccination for people travelling to and from the region.
The global and national mpox situation is changing rapidly, and guidance is likely to change as the situation emerges. If you are a gay, bisexual or other man who has sex with men (GBMSM) in the UK and are currently concerned about on-going mpox transmission of clade 2 in the UK:
Although the 2022 outbreak of mpox clade 2 disproportionately affected GBMSM and their sexual networks, there is currently no evidence to suggest GBMSM are at higher risk of acquiring mpox clade 1b
It is currently assumed that the mpox vaccine provided since 2022 also offers protection against the new clade (1b). This is because clades 1 and 2 are genetically very similar
Partial (one dose) or full (two doses) vaccination offers significant protection against clade 2 - the clade most commonly seen in the UK
There is currently no evidence to suggest booster doses (i.e. a third dose) offer any more protection
For now – and this advice could change – we do not recommend contacting your sexual health clinic for immediate mpox vaccination: instead please wait until your next routine appointment. Clinics are currently under massive pressure
For others in the UK:
If you are intending to travel to DRC or neighbouring countries, please do NOT contact your sexual health clinic for mpox vaccination. Clinics will not be able to assist as they are currently not authorised to issue travel-related vaccines.
If you have recently travelled from the DRC or neighbouring countries and you had sex there or think you may have come into close contact with someone with mpox symptoms, look out for symptoms of mpox (including fever, headaches, and the appearance of a rash or lesions anywhere on the body) and contact NHS 111 for further advice