A snapshot global survey on side effects of COVID-19 vaccines among healthcare professionals and armed forces with a focus on headache

BACKGROUND: New messenger RNA (mRNA) and adenovirus-based vaccines (AdV) against Coronavirus disease 2019 (COVID-19) have entered large scale clinical trials. Since healthcare professionals (HCPs) and armed forces personnel (AFP) represent a high-risk category, they act as a suitable target population to investigate vaccine-related side effects, including headache, which has emerged as a common complaint. METHODS: We investigated the side-effects of COVID-19 vaccines among HCPs and AFP through a 38 closed-question international survey. The electronic link was distributed via e-mail or via Whatsapp to more than 500 contacts. Responses to the survey questions were analyzed with bivariate tests. RESULTS: A total of 375 complete surveys have been analyzed. More than 88% received an mRNA vaccine and 11% received AdV first dose. A second dose of mRNA vaccine was administered in 76% of individuals. No severe adverse effects were reported, whereas moderate reactions and those lasting more than 1 day were more common with AdV (P=0.002 and P=0.024 respectively). Headache was commonly reported regard-less of the vaccine type, but less frequently, with shorter duration and lower severity that usually experienced by participants, without significant difference irrespective of vaccine type. CONCLUSIONS: Both mRNA and AdV COVID-19 vaccines were safe and well tolerated in a real-life subset of HCPs and AFP subjects.