About mpox

Mpox is a viral disease marked by fever, rash and swollen lymph nodes, that can lead to severe illness. Children, pregnant people and people with weakened immune systems, including people living with HIV, are at higher risk for serious illness and death due to complications from mpox.

In the summer of 2022, an unprecedented mpox outbreak across over 100 countries, including countries that were not previously affected, led the WHO to declare a Public Health Emergency of International Concern (PHEIC).

Around that time, the European Commission tasked the VERDI Consortium with investigating the impact of mpox on populations at higher risk of infection or severe disease, such as people living with HIV, pregnant people and children. Timely and concerted public health responses led to a significant decline in new cases in Europe, and the emergency status ended in May 2023.

Despite this progress, mpox continues to affect some countries, with escalating outbreaks, especially in the Democratic Republic of the Congo (DRC).

In mid-2023, new outbreaks in DRC provinces revealed the circulation of multiple viral clades, one of which is disproportionately impacting children and pregnant people. In August 2024, the WHO issued a renewed PHEIC declaration due to the rising cases, highlighting the need for coordinated research to address clinical gaps and prepare for future outbreaks.

VERDI mpox studies

Epidemiological studies

 

Three epidemiological mpox studies are ongoing in VERDI, collecting quantitative and qualitative data in settings which have historically reported mpox cases as well as those newly affected in the 2022 outbreak. The list below gives more information about MASH-1, VERDIQual, paediatric registry, and a study of asymptomatic rectal carriage of the mpox virus in men who have sex with men.

Additional work is ongoing developing harmonised CRFs for collection of data on mpox infections.

Morbidity, Mortality And Risk Factors of Mpox in HIV Negative High Risk Sexual Health Clinic Attenders and People Living With HIV (MASH-1)
  • Partners involved: NEAT-ID
  • Study aims/objectives:
    • Primary
      – To describe and compare outcomes of mpox in people living with HIV (PLWHIV) and an HIV-negative population of people using pre-exposure HIV prophylaxis (PrEP users)
      – To identify risk factors for specific mpox outcomes
    • Secondary
      – To estimate the approximate prevalence of mpox in PLWHIV and PrEP users in this retrospective cohort
      – To describe clinical manifestation of mpox and response to mpox treatment in PLWHIV and PrEP users
      – To describe the co-morbidities in PLWHIV and PrEP users
  • Study design: Cohort study using retrospective, routinely collected clinical data
  • Countries included: UK, Spain, France, Poland
  • Current status: Closed
  • Further information: ClinicalTrials.gov
Qualitative and mixed-methods investigation of mpox in endemic and non-endemic areas (VERDIQual)
  • Partners involved: University College London, Institute of Human Virology Nigeria, Mahidol University, Penta
  • Study aims/objectives:
    – To understand social media representations of mpox
    – To understand social media messaging and public discourse on mpox vaccination
    – To understand lived experiences of mpox including stigma
    – To describe attitudes to and recommendations for public health messaging
  • Study design: Semi-structured interviews, focus group discussions, participatory photography, thematic and linguistic analysis of news and social media
  • Countries included: Nigeria, Italy, Thailand, UK
  • Current status: Ongoing
Mpox paediatric and adolescent clinical study (Paediatric registry)
  • Partners involved: Penta, University College London, European University Cyprus, Servicio Madrileño de Salud, Institute of Human Virology Nigeria, University of Kinshasa
    Study aims/objectives: To collect harmonised data on mpox virus infection in children and adolescents aged <18 years globally, to characterise cases and describe outcomes of infection
  • Study design: Registry collecting anonymised routine clinical data
  • Countries included: Democratic Republic of the Congo, Spain, USA (Open for Global Recruitment: Join Survey)
  • Current status: Ongoing
  • Further information: ClinicalTrials.gov

Modelling studies

 

Four mpox modelling studies have been conducted, summarised in the list below. These aim to estimate important epidemiological parameters such as the reproduction number and incubation period distribution of mpox, and to evaluate the impact of interventions in controlling transmission.

Study of adaptive behavior in response to the 2022 mpox outbreak in the Paris area
  • Partners involved: Institut national de la santé et de la recherche médicale
  • Study aims/objectives:To evaluate the impact of post-exposure prophylaxis (PEP) vaccination, immunity or behavioural changes on the spread of mpox among highly active MSM in the Paris area
  • Countries included: France
  • Current status: Completed
  • Related publications: Adaptive behavior in response to the 2022 mpox epidemic in the Paris region
Estimation of key epidemiological parameters for MPXV clade I, based on historical data from the Democratic Republic of the Congo
Development of a new Bayesian methodology using Laplacian P-Splines to estimate the incubation time for mpox and other infectious diseases
  • Partners involved: University of Hasselt
  • Study aims/objectives: To estimate the incubation distribution from reported exposure times and symptom onset times
  • Countries included: Multicountry
  • Current status: Completed
  • Related publications: Flexible Bayesian estimation of incubation times
Individual-based model to investigate the factors contributing to the decline of the 2022 MPXV clade IIb epidemic in Italy

Last updated: March 2025