If I don’t have side effects, is the COVID vaccine still working?

People have a wide variety of reactions to the vaccine.

Lots of people are vaccinated now, and we are seeing a wide variety of reactions after getting the COVID-19 vaccine. Some people have headaches or fatigue, others get fever or chills. Around 3 out of 4 people report mild side effects, usually within two days of getting the vaccine, and more commonly after the second dose. You have probably heard that these reactions mean your immune system is doing its job and building up antibodies to the virus. But maybe you felt great after your vaccine, and now you’re wondering if it worked.

Feeling sick after the vaccine is normal - but not feeling sick doesn’t mean it isn’t working!

Just because you don’t feel sick from the vaccine doesn’t mean your body isn’t building an immune response. It’s common to not feel sick after many vaccines, even though your body is doing its job. If you don’t have any side effects, do not worry - just enjoy your good luck!

Getting vaccinated is the best way to keep yourself and your family safe from COVID, and to help bring the pandemic to an end. 

Last update: Apr 22, 2021 10:30am ET

Science review: SGB, JAB