Disclaimer: At UPMC HealthBeat, we strive to provide the most up-to-date facts in our stories when we publish them. We also make updates to our content as information changes. However, education about COVID-19 can shift quickly based on new data, emerging variants, or other factors. The information in this story was accurate as of its publish date. We also encourage you to visit other reliable websites for updated information, including the Centers for Disease Control and Prevention (CDC), Food and Drug Administration (FDA), and your state and local governments.
The U.S. Food and Drug Administration has authorized or approved four COVID-19 vaccines. Pfizer-BioNTech, Moderna, Johnson & Johnson/Janssen (J&J), and Novavax developed the vaccines. Millions of Americans have received them so far.
Data show the COVID-19 vaccines are safe and effective.
If you’ve scheduled an appointment to get vaccinated, you may be wondering what to expect after you receive your shot. No matter which manufacturer produced the vaccine you receive, the potential side effects are similar.
What Are the Side Effects of the COVID-19 Vaccine?
According to the Centers for Disease Control and Prevention (CDC), the most common side effects of getting the COVID-19 vaccine are similar to those of getting any immunization.
Many people report having only mild side effects after a COVID-19 vaccination. Some people have no side effects at all.
On the arm where you got your shot, you might have:
Throughout your body over the next few hours or days, you might have:
- Tiredness or fatigue.
In a small number of cases, people have reported that they developed a rash a few days or weeks after the first dose.
A red, itchy, swollen, or painful rash that appears on the arm where you received the shot is called “COVID arm.” Even if you develop COVID arm, the CDC recommends you should still get the second shot when you’re due. Tell your vaccine provider that you got COVID arm after the first dose. Your provider may recommend that you get the second dose in your other arm.
The CDC does not know whether people who experience COVID arm after the first dose will have a similar reaction after the second dose. However, available evidence suggests that having this type of reaction after the first dose does not increase your risk of having a severe allergic reaction after the second dose.
On April 23, 2021, the Centers for Disease Control and Prevention (CDC) and U.S. Food and Drug Administration (FDA) released a statement lifting a nationwide pause in the use of the Johnson & Johnson/Janssen COVID-19 vaccine. Federal health officials investigated cases of a rare, serious blood clot reported in some people after they received the J&J vaccine.
After their investigation, the CDC and FDA determined the risk of blood clots from this vaccine is very low and the known benefits in preventing COVID-19 are very high for people 18 and older, outweighing the risks. The vaccine is safe and effective in preventing COVID-19.
If you or a loved one receives the J&J vaccine, you DO NOT have to take any medications to prevent blood clots. Call your doctor if you experience side effects related to blood clots, including:
- Shortness of breath.
- Chest pain.
- Leg swelling.
- Persistent abdominal pain.
- Severe headaches or blurred vision.
- Easy bruising or tiny blood spots under your skin, beyond the injection site.
The Moderna and Pfizer vaccines have not been linked to the adverse effect of blood clots.
“Most people, regardless of the vaccine they receive, should not expect severe side effects like this,” says Donald Yealy, MD, chief medical officer, UPMC. “It’s exceptionally rare.”
The Centers for Disease Control and Prevention (CDC) is monitoring reports of the heart conditions myocarditis and pericarditis in people who received the Moderna and Pfizer vaccines, especially adolescents and young adults. The Novavax vaccine has also been linked to these conditions.
According to the CDC, the reported cases were rare and happened mostly in male adolescents and young adults 16 and older. Symptoms usually presented within days of vaccination, and patients typically responded well to rest and medications.
The CDC continues to recommend vaccination for Americans 6 months and older.
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Why Does the COVID-19 Vaccine Cause Side Effects?
Soreness in the muscle around the spot where the needle pierced your skin is normal, as is a feeling of tiredness or body aches. These side effects are the result of inflammation caused by your immune system gearing up in reaction to the vaccine. It is helping your body build protection against COVID-19.
“The side effects are from stimulating the immune system,” says Graham Snyder, MD, medical director, Infection Prevention and Hospital Epidemiology, UPMC. “There are some expected side effects, but the large trial data we currently have that was reviewed by the FDA and us shows it’s very safe.”
Some people report temporary swelling of the lymph nodes in their armpits after receiving the vaccine.
Although these side effects may limit your activities for a short time, they should go away in a few days.
What Should I Do if I Experience Side Effects?
If you experience soreness or pain at the site of your shot:
- Apply a clean, cool, wet washcloth over the area.
- Use or exercise your arm.
To reduce discomfort from fever:
- Drink plenty of fluids.
- Dress lightly.
Can I Take Ibuprofen for COVID-19 Vaccine Side Effects?
Talk to your vaccine provider about taking over-the-counter medicines — ibuprofen, acetaminophen, or antihistamines— if you have discomfort after your shot. The CDC says that you may take these medicines if you have no other medical reason that would prevent you from taking them normally.
The CDC does not recommend taking these medicines before your vaccination for the purpose of trying to prevent side effects. It is not known whether these medicines affect how well the vaccine works.
When Should I Call My Doctor if I’m Having Side Effects?
In most cases, discomfort from fever or pain after the vaccine is normal. Contact your primary care provider if:
- Redness or tenderness where you got the shot increases after 24 hours.
- Your side effects are worrying you or do not seem to be going away after a few days.
- You develop COVID arm. Your primary care provider may recommend an antihistamine to relieve the itch and soothe the rash.
If you get a COVID-19 vaccine and think you might be having a severe allergic reaction after you leave the vaccination site, seek immediate medical care by calling 911. Severe allergic reactions almost always occur within the first 30 minutes to four hours after receiving the vaccine. Learn more about the COVID-19 vaccines and rare severe allergic reactions to them.
Call your doctor if you received the J&J vaccine and experience symptoms related to blood clots, including severe headache, arm or leg swelling, and/or difficulty breathing.
Should I Still Get My Second Shot if I Have Side Effects From the First Dose?
Don’t be tempted to skip the second shot of the two-shot vaccines to avoid side effects. If you don’t get the second dose, there is a risk that you have only short-term protection from COVID-19 and may not develop long-term protection.
UPMC encourages vaccination against COVID-19. Visit our website to find out how you can register for a vaccine at UPMC.
Editor's Note: This article was originally published on , and was last reviewed on .
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