Short-term adverse events following modified vaccinia Ankara–Bavarian Nordic (MVA-BN) mpox vaccine with and without concomitant vaccines, Australia, 2022 to 2023

BACKGROUNDModified vaccinia Ankara-Bavarian Nordic (MVA-BN) mpox vaccine is used globally for disease prevention. Real-world safety data following co-administration of MVA-BN with other vaccines is limited.AIMTo characterise the adverse event profile of MVA-BN given alone or concomitantly with other vaccines using data from Australia's active vaccine safety surveillance (AusVaxSafety).METHODSIndividuals (≥ 18 years) who received MVA-BN between 30 August 2022 and 20 April 2023 at sentinel AusVaxSafety surveillance sites and registered via QR code were surveyed on days 7 and 14 post-vaccination regarding adverse events following immunisation (AEFI), medical review by a healthcare professional and impact on daily activities. Analyses included participants who completed both surveys. Outcomes were compared by administration route, dose and concomitant vaccination status.RESULTSAmong 10,943 participants (response rate: 46%; 97% male), 200 (1.8%) received at least one concomitant vaccine. Across 14 days, AEFI rates were comparable or lower in concomitant recipients following intradermal administration (alone: 56% (Dose 1), 36% (Dose 2) vs concomitant: 53% (Dose 1), 32% (Dose 2)) and subcutaneous administration (alone: 49% (Dose 1), 32% (Dose 2) vs concomitant: 28% (Dose 1) and 24% (Dose 2)). Medical review was uncommon (0-2.7%). Impact on daily activities was low across groups (6% vs 3.5%), with most symptoms lasting ≤ 1 day.CONCLUSIONThe frequency and severity of AEFIs within 14 days post-vaccination were similar between concomitant and non-concomitant group. These findings provide preliminary, exploratory evidence supporting the safe co-administration of MVA-BN with other adult vaccines, primarily in adult men, and may help inform future immunisation policy and public health recommendations.