Side Effects: What to Expect

What are the most common side effects of COVID-19 vaccination?

Our bodies' immune system produce a variety of mild symptoms when introduced to a vaccine.  It's a sign our body is producing antibodies to fight the virus. These symptoms are often extremely mild and can include: Sore arm, swollen lymph nodes, chills or fever fatigue, body aches, or feeling run down, joint pain, headache, nausea, vomiting or diarrhea. These symptoms normally resolve within 1-2 days [1,2,3,4]. 

Will I miss work because of my side effects? 

Everyone is affected differently.  While there are a set of common side effects, some individuals can be hit harder than others.  The vaccine does not introduce the COVID-19 virus into your body, so you are not infectious even if you feel sick. Your employer should accommodate you during this short period of time.  Be proactive; being infected with COVID-19 could result in at least 10 days of isolation. 

Graphic illustrating possible COVID-19 vaccine side effects

Even with the vaccine, I can still get COVID, so what’s the point? 

No vaccine is 100% effective, but this does not mean you are not protected.   Clinical trials showed that new mRNA COVID-19 vaccines are 90%+ effective at preventing symptomatic infection [5]. Breakthrough infections are to be expected and many of these breakthrough cases are from variants like Delta.  The small minority of people who become infected with COVID-10 after vaccination and develop symptoms are infectious for a smaller duration of time and have lower viral levels in their bodies, reducing transmission, while also reducing risk of hospitalization and death [6,7].  Vaccines provide the necessary protection for both your own personal health, but also reduces the community transmission that allows for the virus to mutate and the pandemic to continue. 

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  1. Yale Health. COVID-19 Vaccine Side Effects. Accessed Aug 19, 2021. 
  2. NYU Lagone Health. Bracing for COVID-19 Vaccine Side Effects? Here’s What to Expect. May 10, 2021. 
  3. Center for Disease Control. Possible Side Effects After Getting a COVID-19 Vaccine. Updated Aug. 6, 2021. 
  4. Mayo Clinic. What are the vaccines’ side effects? Accessed September 13, 2021. 
  5. Yale Medicine. Comparing the COVID-19 Vaccines: How Are They Different? September 17, 2021. 
  6. Yale Medicine. You've Had a COVID ‘Breakthrough Infection’—Can You Really Spread It to Others? August 11, 2021. 
  7. University of Utah. What We Know About COVID-19 Breakthrough Infections and the Delta Variant. Sep 02, 2021.