Why Your Vaccine Side Effects May Be Different If You've Already Had COVID-19

Vaccine side effects are a sign that your body is building up the immunity to fight off the virus you're being vaccinated for, and are usually a normal occurrence. Common vaccine side effects might include a headache, mild fever, body aches, chills, and fatigue. You could also have some pain and swelling at the site of the injection. Reported side effects of the Moderna and Pfizer COVID-19 vaccines are similar (via the U.S. Health and Human Services). 

Doctors giving out the COVID-19 vaccines are noticing a difference in side effects, though, between people who have COVID-19 and those who haven't had it yet, according to a study posted February 1, 2021. Keep in mind that this study has not been reviewed by peers, nor has it been published. 

The study's authors claim that those who have had COVID-19 are experiencing more severe vaccine side effects than those who have not had the virus before. They're also seeing a difference in antibodies to COVID-19. People who've had COVID-19 seem to have significantly higher antibodies after the first vaccine shot than those who haven't had the virus. The researchers believe that those who've had the virus may only need one dose of the vaccine, but this has yet to be confirmed, so if you've had one dose, make sure you keep your appointment for your second one. If this is true, though, this could make extra shots available for others if recommendations change in the future. 

After your first vaccine dose for COVID-19, you can expect some side effects as listed above. They are common with any vaccine. So, you can expect a mild fever, a headache, chills, feeling more tired than usual, some muscle pain, and some body aches. You can also expect some redness, swelling, and mild pain where you received your shot. These side effects will go away rather quickly, a few days, according to the CDC. 

Stay well hydrated after you get your shot, which can help with any fever symptoms. Contact your doctor if the pain or redness at the shot site gets worse after a day or if your symptoms are not getting better after a few days. Call 911 if you have any signs of a severe allergic reaction, and make sure to talk to your doctor about any previous allergic reactions to vaccines (via CDC). 

While you might have side effects from the vaccine, you still need to get both shots for the vaccine to work properly. Just be prepared for the side effects you may experience after your shots and know that they will go away in a few days. 

There need to be more studies on whether those who've had COVID-19 can go with one shot, so still get both doses of the vaccine even if you've had COVID-19. More studies are needed before those recommendations can be changed.