Some individuals experience side effects to the COVID-19 vaccine including mild to moderate headache, fever, and fatigue that resolves within a day or two. Side effects were more common after the second dose of the mRNA vaccines as well as after the single Johnson & Johnson shot.
In large clinical trials, the COVID-19 vaccines were found to be safe with no serious health effects. Following approval of the Johnson and Johnson vaccine, very rare but serious blood clots were observed, mostly in women under the age of 50. Women under 50 should be aware of this small but increased risk. No increased risk of blood clots have been observed for the mRNA vaccines so these remain a very good option for women under 50. The CDC continues to closely monitor all vaccines for safety.
Rare cases of myocarditis, or inflammation of the heart muscle, were seen in a very small number of teens and young adults after receiving an mRNA vaccine (Moderna or Pfizer). The vast majority of these cases were seen in boys after the second dose and were mild. Myocarditis can also result from COVID infection. After careful review, the FDA determined that the benefits of vaccination against COVID infection outweigh the extremely rare risk of myocarditis.
After you are fully vaccinated there is still a low risk that you may become infected and spread COVID-19. For this reason, it is still important for you to take steps to prevent the spread of COVID-19. Get more information from the CDC about what you can do safely after you are vaccinated.