Timely evidence generation in epidemic response: lessons from an attempted analytical epidemiological investigation during an mpox outbreak, Ireland, 2022.

The emergence of mpox cases in Ireland in May 2022 triggered an urgent public health response, including an attempted analytical epidemiological investigation aimed at informing vaccination strategies and risk communication, particularly among gay, bisexual and other men who have sex with men. At the time of implementation, case numbers had declined to an extent that limited recruitment, resulting in early suspension of data collection. We present a structured reflection of the investigation, drawing on a lessons learnt review and the experiences of those involved, to offer actionable recommendations to strengthen evidence generation in future outbreak preparedness and response efforts. Key lessons include the critical importance of stakeholder engagement, clear governance and legal frameworks, and the need for enhanced procedural preparedness and pre-established surge capacity arrangements to enable rapid analytical investigations during health emergencies. These insights align closely with Ireland's National Health Protection Strategy and the extended mandate of the European Centre for Disease Prevention and Control. Beyond existing international frameworks for outbreak preparedness, this reflection highlights the practical implementation barriers that must be addressed to enable timely and coordinated epidemiological investigations across Europe.