接種疫苗為何會有副作用? 專家曝:免疫系統抵禦現象|Why do some people get side effects after COVID-19 vaccines?

Why do some people get side effects after COVID-19 vaccines? (AP Illustration/Peter Hamlin)


Temporary side effects including headache, fatigue, and fever are signs the immune system is revving up — a normal response to vaccines. And they’re common.

美國食藥署疫苗主管彼得.馬克斯醫生(Dr. Peter Marks)表示,「接種這些疫苗後的第二天,我不會計劃任何劇烈活動」,並表示自己在接種第一劑後感到非常疲勞。

“The day after getting these vaccines, I wouldn’t plan anything that was strenuous physical activity,” said Dr. Peter Marks, the U.S. Food and Drug Administration’s vaccine chief, who experienced fatigue after his first dose.


Here’s what’s happening: The immune system has two main arms, and the first kicks in as soon as the body detects a foreign intruder. White blood cells swarm to the site, prompting inflammation that’s responsible for chills, soreness, fatigue, and other side effects.


This rapid-response step of your immune system tends to wane with age, one reason 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 didn’t feel anything a day or two after either dose, that doesn’t mean the vaccine isn’t working. Behind the scenes, the shots also set in motion the second part of your immune system, which will provide the real protection from the virus by producing antibodies.


Another nuisance side effect: As the immune system activates, it also sometimes causes temporary swelling in lymph nodes, such as those under the arm. Women are encouraged to schedule routine mammograms ahead of COVID-19 vaccination to avoid a swollen node being mistaken for cancer.


Not all side effects are routine. But after hundreds of millions of vaccine doses administered around the world — and intense safety monitoring — few serious risks have been identified.

在接種阿斯特捷利康(AstraZeneca)製藥公司和嬌生集團((Johnson & Johnson))生產的疫苗的人中,有極少數人發現了一種不尋常的血凝塊。有些國家考量到老年人的身體狀況預留了這些疫苗,而監管當局也表示提供這些疫苗的好處仍然大於風險。

A tiny percentage of people who got vaccines made by AstraZeneca and Johnson & Johnson reported an unusual type of blood clot. Some countries reserved those shots for older adults but regulatory authorities say the benefits of offering them still outweigh the risks.


People also occasionally have serious allergic reactions. That’s why you’re asked to stick around for about 15 minutes after getting any type of COVID-19 vaccine — to ensure any reaction can be promptly treated.


Finally, authorities are trying to determine whether temporary heart inflammation that can occur with many types of infections also might be a rare side effect after the mRNA vaccines, the kind made by Pfizer and Moderna. U.S. health officials can’t yet tell if there’s a link but say they’re monitoring a small number of reports, mostly male teens or young adults.