What are the possible side effects of a COVID-19 vaccine?

Among vaccine recipients during the Pfizer clinical trials, 8.8% reported experiencing any reaction they considered to interfere with daily activity; the most common symptoms were fatigue (4.2%), headache (2.4%), muscle pain (1.8%), chills (1.7%), and injection site pain (1.4%). More people experienced these side effects after the second dose.

Among vaccine recipients during the Moderna clinical trials, 9.1% reported local injection site reaction and 16.5% reported side effects, with the most common including fever, headache, fatigue and muscle aches and pains.

No specific safety concerns were identified for the Pfizer and Moderna vaccines in subgroup analyses by age, race, ethnicity, underlying medical conditions, or previous SARS-CoV-2 infection.

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1. Questions about safety & effectiveness
2. How did a vaccine happen so quickly?
3. Can the COVID-19 vaccine make you sick?
4. I received a flu vaccine, so why would I need the COVID-19 vaccine?
5. Concerns about DNA altering
6. Who should receive the COVID-19 vaccine?
7. Concerns about the ingredients used in the COVID-19 vaccines
8. What are the possible side effects of a COVID-19 vaccine?
9. I've been vaccinated. Should I continue to wear a mask, social distance and avoid large gatherings?
10. Why do I need a vaccine when most people recover from COVID-19?
11. If I've recovered from COVID-19, do I still need to get vaccinated?
12. Will vaccines be mandated?