Common COVID-19 Vaccine Questions

February 2024

COVID-19 vaccine guidance has changed over time since the vaccine was first introduced in 2020, so it’s not unusual to have questions. Here are answers to some common COVID-19 vaccine questions.

Who is eligible to receive the COVID-19 vaccine?

The CDC recommends that everyone ages 6 months and older be vaccinated against COVID-19. The FDA has approved COVID-19 vaccines fully for people ages 12 and older, and it has authorized the use of COVID-19 vaccines in children ages 6 months to 11 years.

What can I expect at my vaccination appointment?

You will need to answer a few health-related questions, such as whether you have any allergies to the ingredients in the vaccine, are immunocompromised, or are pregnant. After you receive the vaccine, you’ll need to wait at the testing site for 15 to 30 minutes to ensure you don’t have an allergic reaction. This way, in the unlikely event that you do have an allergic reaction, you will be able to receive prompt and effective care from the center’s experienced staff.

How much will my COVID-19 vaccine cost?

COVID-19 vaccines are now paid for by your insurance company, as well as Medicare and Medicaid. If you do not have insurance, Medicare, or Medicaid, you still can get a free COVID-19 vaccine from the CDC’s Bridge Access Program through the end of December 2024. Healthcare providers participating in this program include local health care clinicians, state and local health departments, and community pharmacies. To find a vaccine site participating in the Bridge Access Program, visit

Are COVID-19 vaccines fully approved?

The FDA initially issued an emergency use authorization (EUA) for COVID-19 vaccines after the FDA reviewed the safety and effectiveness data for the vaccines and determined that it was sufficient to allow the vaccines to be distributed before full approval because the COVID situation was so urgent.

The FDA then continued to review safety and effectiveness data as the vaccines were rolled out. Based on this more extensive data and review, the FDA eventually issued full approval of each vaccine for people ages 12 and older. COVID-19 vaccines for children ages 6 months to 11 years remain authorized under an EUA until the FDA issues full approval.

Do the COVID-19 vaccines have any side effects?

All vaccines, including the COVID-19 vaccines, can have side effects. Vaccine side effects often spring from your body’s reactions to the vaccine, and they’re a normal part of getting vaccinated. They occur because the immune system is responding to the vaccine, which indicates that the vaccine is working.

The most common side effects are redness, swelling, or soreness at the injection site, which most people experience. Your arm probably will be sore for a few days after receiving the COVID-19 vaccine. It’s also common to experience a headache or a general sense of not feeling well. Other possible side effects include nausea, muscle stiffness, soreness, and muscle or joint aches. If you experience other symptoms aside from those above, contact a health care provider to report what you’re feeling.

Some rarer side effects have occurred with COVID-19 vaccines. One known rare side effect is inflammation in the muscle in or around the heart, i.e., myocarditis or pericarditis. Symptoms can begin a week after vaccination and include chest pain, shortness of breath, and a fast or pounding heartbeat. This condition usually goes away on its own and is usually milder and less common than myocarditis or other heart problems caused by the COVID-19. If you experience any of these symptoms, contact a health care provider for medical advice. Myocarditis after the vaccine is less common in young females and extremely uncommon in people over age 30. It occurs in about two to 10 out of every 1 million females under age 30, about 40 to 70 out of every 1 million males under age 24, and about 15 to 18 out of every 1 million males in their late 20s.

After getting the COVID-19 vaccine, when will my protection start and when will it wear off?

The immune response to a COVID-19 vaccine begins to protect you against the disease about one to two weeks after you get vaccinated. You receive the most protection from vaccination after you receive both your initial series doses or after receiving the updated vaccine if you were vaccinated previously. Remember that it is still possible to get sick with COVID-19 after vaccination, but the disease usually is much shorter and milder, with lower risk of hospitalization and death if you’re vaccinated.

Scientists don’t know exactly how long protection from COVID-19 vaccines lasts, partly because immunity to a past variant of the SARS-CoV-2 virus may not work as well against a newer variant. That’s why researchers developed additional versions of COVID-19 vaccines after the first ones were released.

Going forward, scientists and health care providers expect that an updated COVID-19 vaccine will be needed about once a year. This will allow the vaccine to keep up with changes to the virus that causes COVID-19. (Similarly, flu vaccines are updated seasonally.)

Are the COVID-19 vaccines safe?

Getting a COVID-19 vaccine is the safest way to reduce your risk of contracting COVID-19. These vaccines were tested on more than 70,000 people in clinical trials. Since this extensive testing, more than 670 million Americans have received these vaccines.

A small proportion of people with histories of severe allergic reactions experienced anaphylactic reactions to the vaccines. These people recovered with treatment. However, people who are allergic to the COVID-19 vaccines’ ingredients, including polyethylene glycol (PEG) and polysorbate, should not receive these vaccines.

The FDA and CDC continue to monitor the safety of COVID-19 vaccines. People can report unexpected side effects or other adverse events from the vaccines to the Vaccine Adverse Event Reporting System (VAERS).

Can a COVID-19 vaccine make me sick with COVID-19?

No, the COVID-19 vaccines cannot give you COVID-19. You may feel unwell for a day or two after receiving the vaccine because of the possible side effects discussed above, but you cannot contract COVID-19 from the vaccines.

What types of COVID-19 vaccines are available?

Many vaccines contain parts of the viruses or bacteria that cause the disease. Other vaccines contain whole viruses or bacteria that have been deactivated or weakened so that they cannot cause illness. These weakened, dead, or partial pathogens then stimulate the immune system to build a defense against diseases.

Two types of COVID-19 vaccines are available: mRNA and protein-based (which contains a part of the virus that causes COVID-19).

mRNA vaccines

Several of the COVID-19 vaccines available are mRNA vaccines, which do not contain any part of the pathogen at all. Instead, mRNA vaccines contain a tiny strip of genetic material (called “messenger RNA”) that contains instructions about how to make a single protein, called the spike protein, from the SARS-CoV-2 (the virus that causes COVID-19).

When the immune system encounters the spike protein, it builds antibodies — special proteins that fight disease. If the SARS-CoV-2 virus enters the body, the immune system will recognize the spike protein and send the antibodies it already has produced to destroy the virus.

Protein-based vaccines

Other COVID-19 vaccines are protein-based and are made the same way as many previous vaccines. Instead of providing instructions for making the spike protein, this vaccine includes the spike protein itself. The immune system then makes antibodies to fight the spike proteins.

For more information and the latest updates on the COVID-19 vaccines, visit the CDC’s Vaccines for COVID-19 page.

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