factually
Index/Topics/mRNA COVID-19 vaccine side effects

mRNA COVID-19 vaccine side effects

The side effects of mRNA COVID-19 vaccines, including common short-term reactions and rare but serious events like myocarditis.

Fact-Checks

2 results
Jan 9, 2026

What are the most frequently reported adverse reactions to mRNA vaccines in clinical trials?

Clinical trials and early observational analyses consistently show that the most frequently reported adverse reactions to mRNA COVID-19 vaccines are local reactions—chiefly injection‑site pain—and tra...

Jan 6, 2026

What are common short-term side effects after mRNA COVID-19 vaccines and their usual duration?

Common short-term reactions after mRNA COVID-19 vaccines are predictable, usually mild-to-moderate and self-limited — injection‑site pain, fatigue, headache, muscle aches, chills and transient fever a...