Frequently Asked Questions about COVID-19 Vaccines
COVID-19 vaccination is recommended for everyone age 6 months and older in the US, including pregnant or breastfeeding women. Updated COVID-19 vaccines are now recommended for everyone age 6 months and older.
Getting COVID-19 vaccines at the same time as other routinely recommended vaccines is safe and convenient.
Information about COVID-19 vaccines changes rapidly. View the latest information on COVID-19 vaccination from the Centers for Disease Control and Prevention (CDC) and the US Food and Drug Administration (FDA).
About the Vaccines
Yes, COVID-19 vaccination is recommended regardless of whether or not an individual was previously infected. Vaccination induces a higher antibody response than natural infection.
The Food and Drug Administration has approved and authorized for emergency use updated COVID-19 vaccines (2023-2024 formula) that include a monovalent (single) component that corresponds to the omicron variant XBB.1.5 of SARS-CoV-2. These vaccines were updated to provide better protection against COVID-19 caused by circulating variants as we head into 2024.
All eligible individuals are encouraged to get vaccinated as soon as possible.
Data show that all of the COVID-19 vaccines currently approved or authorized in the US are highly effective in reducing risk of severe disease, hospitalization, and death. The emergence of new variants further emphasizes the importance of vaccination and other prevention efforts needed to protect against COVID-19.
Viruses constantly mutate, and public health experts expect new variants of a virus to occur. Scientists are monitoring changes in the virus, and information about these variants is rapidly emerging. Vaccines work well in preventing severe illness, hospitalization, and death.
The vaccines from Pfizer and Moderna are messenger RNA (mRNA) vaccines. mRNA is found in all living cells, and mRNA vaccines work by teaching cells how to make a protein or a piece of a protein that triggers an immune response inside the body. That immune response, which produces antibodies, is what protects against infection if you are exposed to the virus.
mRNA is not the same as DNA, and it cannot combine with our DNA to change our genetic code. It is also relatively fragile, and will only remain inside a cell for about 72 hours, before being degraded. mRNA vaccines do not affect or interact with DNA in any way. mRNA never enters the nucleus of the cell, which is where DNA (genetic material) is located.
All vaccines used in the US are required to go through extensive safety testing before they are authorized or licensed by the US Food and Drug Administration (FDA) and recommended for widespread use by the Centers for Disease Control and Prevention (CDC).
Recommended COVID-19 vaccines have been studied in multiple clinical trials, each of which has included thousands of individuals who were followed for a minimum of two months. Decades of experience with other vaccines indicate that the vast majority of adverse reactions occur within the first two months of vaccination.
All COVID-19 vaccines continue to undergo intensive safety monitoring, including using several vaccine reporting systems to ensure the safety of COVID-19 vaccines. Millions of COVID-19 vaccine doses have been given around the world, and serious adverse events are rare.
COVID-19 vaccination is recommended for women who are pregnant, breastfeeding, trying to get pregnant, or might become pregnant in the future. Pregnant and recently pregnant women are more likely to get severely ill with COVID-19 compared with non-pregnant people. Breastfeeding is rarely a safety concern with vaccines.
There is no evidence that COVID-19 vaccines impact fertility or are harmful to the mother or infant.
The American College of Obstetricians and Gynecologists (ACOG) and other experts strongly recommend that pregnant women be vaccinated against COVID-19.
It typically takes a few weeks for the body to build immunity after vaccination, so it is possible to be infected with the virus that causes COVID-19 before or after vaccination. The vaccines help protect against severe disease and related complications including hospitalization and death, but are not as effective in preventing mild COVID-19 infections.
None of the vaccines contain the live virus that causes COVID-19, so it is not possible to get the disease from the vaccine.
Severe allergic reactions to vaccines are rare but can happen. People who have had severe allergic reactions to other vaccines or injectable therapies should consult a healthcare professional with expertise in allergy or immunology for advice before getting vaccinated against COVID-19.
If you have had a possible allergic reaction to a COVID-19 vaccine, you should discuss the reaction and type of vaccine with a healthcare professional. CDC offers additional guidance on allergic reactions after COVID-19 vaccination.
Multiple studies show that older adults and those with certain medical conditions—including cancer, chronic kidney disease, chronic lung disease, dementia, diabetes (type 1 or type 2), Down syndrome, heart disease, HIV, liver disease, and sickle cell disease—are at higher risk of severe illness or death from COVID-19 and should be vaccinated. COVID-19 vaccines are safe and effective.
There have been rare reports of inflammation of the heart (myocarditis or pericarditis) following vaccination with the mRNA COVID-19 vaccines (Pfizer-BioNTech and Moderna) and protein-based COVID-19 vaccine (Novavax). Most of the reported cases have been among male adolescents and young adults and have occurred within several days following the second dose of the vaccine. Most patients with myocarditis and pericarditis who received care responded well to medicine and rest and quickly recovered.
The known and potential benefits of COVID-19 vaccination outweigh the risks. The risk of myocarditis is up to 6 times higher after COVID-19 infection than after mRNA vaccination.
Symptoms of myocarditis or pericarditis can include:
- Chest pain
- Shortness of breath
- Feelings of having a fast-beating, fluttering, or pounding heart
If you are experiencing any of these symptoms, particularly if it is within a week after COVID-19 vaccination, seek immediate medical care.
CDC is actively monitoring these reports and continues to recommend COVID-19 vaccination for everyone age 6 months and older.
Yes. According to the Centers for Disease Control and Prevention (CDC), COVID-19 vaccines and many other recommended vaccines may be given at the same time.
For additional information, view current CDC guidance on coadministration of COVID-19 vaccines and view the NFID animated video, Maintaining Your Health Isn’t Much Different Than Maintaining Your Car.
Even if you are up to date on COVID-19 vaccination, CDC still recommends wearing a face mask in certain instances, and you still need to follow guidance at local businesses, schools, and workplaces.
Anyone wishing to protect themselves from infection may choose to wear a face mask regardless of the level of COVID-19 transmission. If levels of COVID-19 are high in your community, CDC recommends that everyone wear a mask. When levels are at medium, people at higher risk of severe disease should mask, including those with a weakened immune system, people with certain medical conditions, pregnant women, and older adults.
If you are at increased risk for severe disease or if someone in your household is at increased risk for severe disease, you may choose to wear a mask regardless of the level of transmission in your area.
Face masks are not recommended for children younger than age 2 years or for individuals who have trouble breathing or who cannot easily remove them.
Side effects may include a sore arm, pain, swelling or redness at the injection site, fever, fatigue, or other symptoms. These symptoms are normal, should be expected, and are a sign that the body is building immunity. These side effects usually go away in a few days.
Side effects are normal signs that the body is building immunity. These side effects usually go away in a few days. Over-the-counter medicines, such as aspirin, antihistamines, or acetaminophen, may help relieve fever, pain, or discomfort after getting vaccinated—but should not be used before getting vaccinated.
To reduce pain and discomfort in the arm, apply a clean, cool, wet washcloth over the area, and use/exercise your arm gently. To reduce discomfort from fever, drink plenty of fluids and dress in layers that can be removed.
There is no need to delay getting vaccinated against COVID-19 until after surgery. Fever is a potential side effect of COVID-19 vaccines, and having a fever after surgery raises concerns about a possible surgical wound infection. For that reason, it is a good idea to allow at least one week between getting vaccinated and having surgery.
Authorized COVID-19 vaccines are safe for most people, with few exceptions:
- Current vaccines are not authorized for children younger than age 6 months
- People who have a severe allergic reaction after receiving a COVID-19 vaccine or have an allergy to a component in the vaccine should not receive that vaccine and should consult a healthcare professional with expertise in allergy or immunology
Interaction with Antibiotics and Other Drugs
COVID-19 vaccines do not interfere with the vast majority of prescription and over-the-counter drugs that can be taken safely and effectively by those receiving COVID-19 vaccines. Talk to a healthcare professional if you have specific questions about your medical care.
COVID-19 vaccines do not influence or interact with antibiotics, so when indicated, antibiotics may be taken at any time relative to COVID-19 vaccine administration.
Do not take a pain reliever or fever-reducing drug before receiving a COVID-19 vaccine because these drugs may impact the immune response to the vaccine. If you experience side effects after getting vaccinated, it is safe to take these drugs as needed to treat pain. Patients routinely taking low-dose aspirin or anti-inflammatory medications may continue to take these medications as recommended.
Updated October 2023
Sources: Centers for Disease Control and Prevention, Food and Drug Administration