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New Vaccine Side Effect "COVID Arm" Striking Patients, Say Doctors

Everything you should know about the latest symptom associated with the vaccine.

While the COVID-19 vaccine has been deemed safe and effective by the CDC and FDA, there are a few side effects being reported by those who have already been injected. One of them? COVID arm, which seems to be attracting a lot of attention, likely due to its dramatic sounding nature. What is it exactly and how concerned should you be about the scary sounding symptom? Eat This, Not That! asked Yale Medicine dermatologist and assistant professor at Yale School of Medicine Alicia Little, MD, Ph.D. to reveal everything there is to know about it. Read on to learn about COVID arm—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had Coronavirus.  


What Is COVID Arm?

Courtesy of New England Journal of Medicine

COVID arm, which should be more accurately referred to as "COVID vaccine arm" per Dr. Little, is a delayed hypersensitivity reaction to a component of the COVID vaccine. "It is a red, sometimes itchy or tender localized reaction near the vaccine injection site that occurs most frequently about 7 days after the vaccine, though it can occur as late as two weeks post-vaccine," she explains. It usually lasts around fives days, though sometimes it may last a shorter or longer time, and most reports have been in response to the Moderna COVID vaccine.


Why Does it Happen?

Scientist in laboratory studying and analyzing scientific sample of Coronavirus monoclonal antibodies to produce drug treatment for COVID-19.

Dr. Little explains that COVID arm is an immune reaction to a component of the vaccine. However, experts still aren't sure which component it is reacting to. "The reaction is most likely caused by the T-cells in the immune system, which may take several days to initially get activated, but can respond to the same trigger more quickly the second time around," she says. Because vaccines are supposed to activate the immune system, "it's possible the condition may be related to the immune response we are trying to generate to the COVID spike protein, or it may be an immune response that is not directly related to developing immunity to COVID," she continues.


What Should You Do If You Experience COVID Arm?

Female pharmacist with protective mask on her face working at pharmacy.


Per Dr. Little, COVID vaccine arm is NOT something to be worried about. "People who experience COVID arm can and should get their second dose of vaccine," she affirms. However, it may help to get the second dose in the opposite arm, and if the rash is very itchy or tender, it may help to use topical steroids like hydrocortisone or to speak with your doctor. 


When COVID Arm Occurs

Doctor in personal protective suit or PPE inject vaccine shot to stimulating immunity of woman patient at risk of coronavirus infection.

And, Dr. Little notes that of her patients, at least half of the people who had COVID vaccine arm to the first vaccine dose get it again the second time, "but the second COVID vaccine arm reaction usually occurs sooner than the first reaction and lasts a shorter period of time," she says."Importantly, this reaction is not a sign of a worrisome allergy and it is not a reason to not get your second vaccine dose," she reminds. 

RELATED: Doctor Warns "Do Not" Do This Before Your Vaccine


What to Do if You Get COVID Arm and Other Side Effects

Doctor and senior woman wearing facemasks

The CDC has warned that vaccine side effects include:

  • Pain
  • Redness
  • Swelling

As well as

  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Fever
  • Nausea

Contact your doctor if you feel you need medical attention. And get vaccinated when it becomes available to you, and to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.

Leah Groth
Leah Groth has decades of experience covering all things health, wellness and fitness related. Read more about Leah