Modelling vaccination and control strategies of outbreaks of monkeypox at gatherings

BackgroundMonkeypox cases keep soaring in non-endemics countries and areas in the last few months, leading to the WHO declaring a Public Health Emergency of International Concern. The ongoing and coming festivals, parties and holidays gathering events are causing increased concerns about possible outbreaks. MethodsWe considered a hypothetical metropolitan city and modelled the transmission of monkeypox virus in humans in high-risk (HRG) and low-risk groups (LRG) using a Susceptible-Exposed-Infectious-Recovered (SEIR) model and incorporated gathering events. Model simulations assessed how the current vaccination strategy combined with other public health measures can contribute to mitigating or halting outbreaks from mass gathering events. ResultsThe risk of a monkeypox outbreak remains high on the occasion of mass gathering events in the absence of public health control measures. However, the outbreaks can be well controlled by cutting off transmission by isolating confirmed cases and inoculating their close contacts. Also, Post Exposure Prophylaxis is more effective for containment in the summer gatherings than a broad vaccination campaign in HRG, considering the time needed for developing the immune response and the availability of vaccine. The number of attendees and effective contacts during the gathering are the factors that need more attention by public health authorities to prevent a burgeoning outbreak. Moreover, restricting attendance through vaccination requirements can help secure mass gathering events. ConclusionGathering events can be made safe with some restrictions of either the number and density of attendees in the gathering, or vaccination requirements. The ring vaccination strategy inoculating close contacts of confirmed cases may not be enough to prevent potential outbreaks, however, mass gatherings can be rendered safe if that strategy is combined with public health measures, including rigorous contact tracing, testing, identifying and isolating cases. Compliance of the community and promotion of awareness are also indispensable to the containment.