• Almost two billion doses of the mRNA covid-19 vaccines tozinameran (Comirnaty°) and elasomeran (Spikevax°) have been administered as of mid-2022 for the prevention of covid-19 in many countries.
   
• Based on data accrued over about one and a half years of clinical experience with these vaccines, numerous, generally non-serious adverse effects have been identified, in particular: local reactions, reactions related to the vaccination process, flu-like symptoms, myalgia, lymphadenopathy, hypersensitivity reactions and hypertension.
   
• A number of atypical adverse effects were recognised in 2021-2022, such as myocarditis, mainly reported in adolescent males or young men under the age of 30 years, especially with elasomeran; and cases of multisystem inflammatory syndrome ("PIMS") have been reported in adolescents.
   
• Other safety signals have been detected, where no link with vaccination could be established.
   
• Reviews of reported adverse effects by several drug regulatory agencies and epidemiological studies found no link between vaccination and certain safety signals such as thrombosis, pulmonary embolism and acute myocardial infarction.

©Prescrire 1 November 2022

Source: "Messenger RNA covid-19 vaccines: a review of adverse effects, as of mid-2022" Prescrire International 2022; 31 (242): 270-274. Subscribers only.

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