COVID-19 vaccines - what to expect
COVID-19 vaccines are used to prepare the body's immune system to protect against COVID-19. Adults and children ages 6 months and older should get the COVID-19 vaccination.
COVID-19 vaccines
COVID-19 vaccines are used to prepare the body's immune system to protect against COVID-19. Everyone ages 6 months and older should get a 2024-2025 C...

Children ages 6 months and older
COVID-19 vaccines are used to prepare the body's immune system to protect against COVID-19.

Learn what to expect before and after you are vaccinated for COVID-19.
COVID-19
Coronavirus disease 2019 (COVID-19) is a respiratory illness that causes fever, coughing, and shortness of breath, but many other symptoms can occur....

BEFORE YOU GET THE VACCINE
There are several ways to sign up for a vaccine:
- Ask your health care provider if they offer COVID-19 vaccines.
- Check your local pharmacy's website or call the pharmacy to see if vaccination appointments are available.
- Contact your state or local health department to find additional vaccination locations in the area.
- Check the Centers for Disease Control and Prevention (CDC) website Vaccines.gov to find out where to get a vaccine in your area.
If you take any medicines, you should keep taking them as you usually do. If you take medicines that affect the immune system, talk with your provider to find out if getting the COVID-19 vaccine will work or cause any problems for you.
You should not take over-the-counter (OTC) pain relievers such as aspirin, ibuprofen, or acetaminophen to help prevent side effects before you get the vaccine. It is not known if these medicines will affect how well the vaccine works. However, if you take these medicines regularly for other reasons, you can take them as you always do.
You should also not take antihistamines to help prevent an allergic reaction before you get the vaccine.
If you have any questions about your medicines, ask your provider or the vaccine provider.
DURING YOUR VACCINE APPOINTMENT
At your appointment, the vaccine provider will tell you if you need to stay at the site afterwards for any needed monitoring. You should receive a vaccination card (or access to a vaccine record website) that tells you what vaccine you received and the date and location you received it. Be sure to keep this information in case it’s needed for future use.
VACCINE SIDE EFFECTS
While COVID-19 vaccines will not make you sick with COVID-19, they may cause certain side effects and flu-like symptoms. This is normal. These symptoms are a sign that your body is making antibodies against the virus.
Common side effects include:
- Pain, redness, and swelling on the arm where you got the shot
- Tiredness
- Headache
- Muscle pain
- Chills
- Fever
- Nausea
- Swollen lymph nodes
Some people get a red, itchy, swollen, painful rash in the arm where they got the shot. This is known as COVID arm. This can occur days after getting the first shot. You should still get your second shot if you got a 2-dose vaccine. You can ask to have it in the other arm.

Arm Rash After COVID-19 Vaccination
COVID-19 vaccines may cause certain side effects in some people. These symptoms can be a sign that your body is making antibodies against the virus. One common side effect is a red, itchy, warm, painful, swollen rash on the arm where you got the shot. This rash, which can be large, is also known as “COVID arm.” It may develop a few days to a week after getting the vaccine. While it may be uncomfortable, this reaction is harmless. You can take an antihistamine or an over-the-counter pain medicine to relieve itching and pain. Even if you have a rash after vaccination, it is important to get further shots as needed. If you are scheduled for a second shot, you may want to get it in the other arm or see if an alternative vaccine is available.
To help relieve side effects, you should:
- Move the arm where you got the shot often during the day
- Apply a clean, cool washcloth to ease swelling and discomfort
- Drink plenty of fluids
- Dress lightly if you have a fever
Note that the side effects from the second dose may be more intense than those from the first shot. Symptoms from the shot may make you feel bad enough that you need to take time off from work or daily activities, but they should go away within a few days. Even if you do have side effects, it is still important to get the second shot. The risks of any side effects from the vaccine are far less dangerous than the potential for serious illness or death from COVID-19.
You may be instructed by the vaccine provider that you can take an antihistamine or acetaminophen or another OTC medicine such as ibuprofen or aspirin to help relieve any vaccine side effects. Or, talk with your provider about taking OTC medicine if you are not sure.
If symptoms do not go away in a few days, or if you have any concerns, you should contact your provider.
When to Call the Doctor
Contact your provider if you have any questions or concerns about COVID-19 vaccines.
In rare cases, people have had severe and non-severe allergic reactions to the COVID-19 vaccines. If you have a severe allergic reaction (anaphylaxis) after getting the first shot of the COVID-19 vaccine, you should not get the second shot. Talk with your provider to see if there are other options.
If you think you are having a severe reaction to a COVID-19 vaccine after leaving the vaccination site, you should call 911 or the local emergency number right away. Symptoms of severe allergic reaction appearing in the first 4 hours after receiving the vaccine include:
- Difficulty breathing, coughing, wheezing, or high-pitched breathing sounds
Difficulty breathing
Breathing difficulty may involve:Difficult breathing Uncomfortable breathingFeeling like you are not getting enough air
ImageRead Article Now Book Mark ArticleWheezing
Wheezing is a high-pitched whistling sound during breathing. It occurs when air moves through narrowed breathing tubes in the lungs.
ImageRead Article Now Book Mark Article - Swelling of the face, eyes, tongue, or throat
- Hives, itchiness, redness of the skin
Hives
Hives are raised, often itchy, red bumps (welts) on the surface of the skin. They can be an allergic reaction to food or medicine. They can also ap...
ImageRead Article Now Book Mark Article - Lowering of blood pressure
Symptoms of severe reactions may also include:
Severe reactions
Anaphylaxis is a life-threatening type of allergic reaction.

- Abdominal pain
- Chest discomfort or tightness
- Diarrhea
- Difficulty swallowing
- Dizziness or lightheadedness
- Nausea or vomiting
- Palpitations
- Slurred speech
- Unconsciousness
If you notice any unusual or concerning symptoms, seek medical care right away.
Rare cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the outer lining of the heart) have been reported in children and teens ages 5 years and older after getting a COVID-19 vaccine.
Myocarditis
Myocarditis is inflammation of the heart muscle. The condition is called pediatric myocarditis when it occurs in children.

Pericarditis
Pericarditis is a condition in which the sac-like covering around the heart (pericardium) becomes inflamed.

This reaction has tended to occur more often in male adolescents and young adults ages 12 to 39 years. However, it also has occurred in females, in other age groups, after other doses, and after receiving the Novavax vaccine.
- It occurs more often after the second dose, most often within 7 days after vaccination. Studies show that this rare risk may be reduced by waiting 8 weeks between the first and second dose.
- With proper care and rest, most people who had the reaction got better quickly without any lasting effects.
- For people who had this rare reaction, it is important to talk with a cardiologist (heart doctor) about how and when to return to exercise and sports.
Symptoms of myocarditis and pericarditis include:
- Chest pain
- Shortness of breath
- Fast-beating heart, fluttering, or pounding heart
If your child or teenager has any of these symptoms, get medical help right away.
All these associations are so rare that they should not cause hesitation in receiving any of these vaccines.
CDC recommends that people may still get vaccinated if they have a history of:
- Severe allergic reactions not related to vaccines or injectable medicines -- such as food, pet, venom, environmental, or latex allergies
- Allergies to oral medicines or a family history of severe allergic reactions
Reviewed By
Linda J. Vorvick, MD, Clinical Professor Emeritus, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Centers for Disease Control and Prevention website. Vaccine safety: Coronavirus Disease 2019 (COVID-19) Vaccine Safety. www.cdc.gov/vaccine-safety/vaccines/covid-19.html. Updated January 31, 2025. Accessed February 20, 2025.
Centers for Disease Control and Prevention website. Staying up to date with COVID-19 vaccines. www.cdc.gov/covid/vaccines/stay-up-to-date.html. Updated January 7, 2025. Accessed February 20, 2025.
Centers for Disease Control and Prevention website. COVID-19 vaccines. www.cdc.gov/covid/vaccines/index.html/. Updated September 10, 2024. Accessed February 20, 2025.