The possible effect of sociobehavioral factors and public health actions on the mpox epidemic slowdown.

Objectives: A pre-exposure vaccination campaign to prevent the spread of the mpox virus was initiated in Italy in August 2022. We explore the possible factors affecting the trend of mpox cases in an Italian region (Lazio) with a rapid roll-out of the vaccination campaign.

Methods: We estimated the impact of the communication and vaccination campaign by fitting a Poisson segmented regression model. Results By September 30, 2692, high-risk men who have sex with men had received at least one dose of vaccine, with a vaccination coverage of 37%. The analysis of surveillance data showed a significant decreasing trend in the number of mpox cases starting from the second week after vaccination (incidence rate ratio 0.452 [0.331-0.618]).

Conclusion: The reported trend in mpox cases is likely to result from a combination of multiple social and public health factors combined with a vaccination campaign.