Why do some people get side effects after COVID-19 vaccines?
Temporary side effects, including headache, fatigue and fever, are signs that the immune system is fluctuating – a normal response to vaccines. And they are common.
[TRENDING:[TRENDING:[TRENDING:[TRENDING:Red-haired reptiles roam the Fla. | Boy trapped in winding gate dies | Aiden Fucci’s mother arrested in murder case]
“The day after receiving these vaccines, I would not plan anything that was strenuous physical activity,”
Here’s what happens: The immune system has two main arms, and the first one kicks in as soon as the body detects a foreign intruder. White blood cells swarm to the site, causing inflammation, which is responsible for chills, soreness, fatigue and other side effects.
This rapid reaction step in your immune system tends to diminish with age, a reason why younger people report side effects more often than older adults. Also, some vaccines simply elicit more reactions than others.
That said, everyone reacts differently. If you did not feel anything a day or two after each dose, it does not mean that the vaccine is not working.
Behind the scenes, the shots also set in motion the second part of your immune system, which will provide the real protection against the virus by producing antibodies.
Another annoying side effect: When the immune system is activated, it also sometimes causes temporary swelling in lymph nodes, such as those under the arm. Women are encouraged to schedule routine mammograms prior to COVID-19 vaccination to avoid confusing a swollen lump with cancer.
Not all side effects are routine. However, after hundreds of millions of vaccine doses administered worldwide – and intense safety monitoring – few serious risks have been identified. A small percentage of people who received vaccines manufactured by AstraZeneca and Johnson & Johnson reported an unusual type of blood clot. Some countries reserved these shots for older adults, but regulators say the benefits of offering them still outweigh the risks.
People also occasionally have severe allergic reactions. Therefore, you are asked to hold on for approx. 15 minutes after receiving any COVID-19 vaccine – to ensure that any reaction can be treated immediately.
Finally, authorities are trying to determine if temporary heart inflammation, which can occur with many types of infections, can also be a rare side effect after the mRNA vaccines, the kind manufactured by Pfizer and Moderna. U.S. health officials cannot yet say if there is a link, but say they monitor a small number of reports, mostly male teens or young adults.
AP answers your questions about coronavirus in this series. Submit them to: FactCheck@AP.org. Read more here:
Can COVID-19 vaccines affect my period?
How long does the protection against COVID-19 vaccines last?
Can employers make COVID-19 vaccination mandatory?
Copyright 2021 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or distributed without permission.