Reporting suspected adverse reactions to COVID-19 vaccines in Portugal: side effects per vaccine type, gender, and age up to July 2021

dverse drug reactions (ADRs) of COVID-2019 vaccines require close monitoring. This study aimed to describe and discuss the most frequent ADRs of COVID-2019 vaccines and their prevalence per age group, gender, and vaccine type in Portugal up to 22 July 2021. ADR reports of COVID-19 vaccines were collected from a public report of INFARMED, I.P. (the Portuguese Medicines Agency). There were 11,314 ADRs notified per 11,002,983 COVID-19 vaccines administered in Portugal - 1 ADR per 1,000 vaccines administered and 0.4 serious ADR per 1,000 vaccines administered. The most commonly reported ADRs were myalgia, headache, pyrexia, pain at the injection site, and fatigue. More ADRs occurred in women and younger individuals. A slightly higher percentage of reported ADRs occurred with Vaxzervria. In conclusion, ADRs were mainly related to non-serious reactions. COVID-19 vaccines maintain a favourable safety profile in Portugal, although the types and prevalence of ADRs are likely to differ between different types of COVID-19 vaccines. Men may need to be motivated to more frequently report ADRs. Keywords: COVID-19; adverse drug reactions; vaccination; COVID-19 vaccines; pharmacovigilance