COVID-19: Vaccine

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Vaccine Facts

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Three COVID-19 vaccines are available in the U.S.: Pfizer-BioNTech (Pfizer), Moderna and Johnson & Johnson/Janssen (Johnson & Johnson). These vaccines are safe and very effective, especially in preventing severe COVID-19 illness, hospitalization and death. Hundreds of millions of COVID-19 vaccine doses have safely been administered in the U.S.

These vaccines are the best protection we have against COVID-19. No matter how old or healthy you are, COVID-19 can lead to hospitalization, long-term health problems and death. Even if you had COVID-19, it is important to get vaccinated because it lowers your risk of getting COVID-19 again. Getting vaccinated also helps protect those around you. This includes people who cannot be vaccinated, such as children younger than 5.

Getting Vaccinated

Currently Eligible

People ages 5 and older are eligible for vaccination.

Studies are ongoing for all three vaccines to see if they are safe and effective for younger children.

Where to Get Vaccinated

You can get the vaccine at many hospitals, community clinics and pharmacies, and at City- and State-run vaccination sites. Many sites, including all City-run sites, allow vaccinations without an appointment, and many sites have same-day appointments. You can also check with your health care provider or local pharmacy to see if they are offering vaccination.

To find a vaccination site:

  • Visit the NYC Vaccine Finder.
  • If you need help making an appointment at a City-run vaccination site, call 877-VAX-4NYC (877-829-4692) and press 1 when asked.
  • NYC residents who are homebound or at least 65 years old can also be vaccinated for free at home. You can sign up online or call 877-VAX-4NYC (877-829-4692) to learn more about in-home vaccination.

Access for Homebound People, People with Disabilities, Older Adults

All NYC residents who are homebound or at least 65 years old can also be vaccinated at home. You can sign up online for an in-home vaccination or call 877-VAX-4NYC (877-829-4692).

Many vaccination sites are accessible to people with disabilities. On the NYC Vaccine Finder, accessible sites are noted with a physical accessibility icon next to the address. The lack of a symbol does not mean the site is inaccessible, just that its accessibility information is not available. Whenever possible, call ahead if you have access questions.

See the Mayor’s Office for People with Disabilities website for answers to frequently asked questions the disability community may have about vaccination access.

For questions or assistance arranging transportation or in-home vaccination, call 877-VAX-4NYC (877-829-4692).

Access for People Younger than 18 Years

At this time, people 5 to 17 years old can get only the Pfizer vaccine. You can search for a site offering the Pfizer vaccine on NYC Vaccine Finder. Also, check with your child’s pediatrician to see if they are offering vaccination.

A parent or guardian must consent for their child to be vaccinated. Consent can be given in person at the time of vaccination or by phone. Some vaccination providers, including all City-run sites, accept proof of consent in writing. Children ages 5 to 15 must have an adult accompany them to a vaccination site.

If the child does not have proof of age, a parent or guardian can attest to their age at the vaccination site.

Check with the vaccination site to make sure they are vaccinating children and about the site’s consent procedures.

Diagnostic/Antibody Testing Not Needed Before Vaccination

You do not need to be tested for COVID-19 infection or for COVID-19 antibodies before being vaccinated.

Vaccination is recommended for people who previously had COVID-19 even if they test positive for antibodies. It is possible to get COVID-19 again, and vaccination strengthens your natural immunity.

No Payment or Social Security Number Required for Vaccination

Vaccination is free for everyone. You will not be charged, even if you do not have health insurance. If you have insurance, bring your insurance card. Your insurance may be billed by the vaccination provider; however, you will not be charged a copay or any other fee. You do not need to provide your social security number to get vaccinated.

No one should charge you a fee or ask for your credit card information or social security number. If they do, it is likely a scam or fraud, and you should go elsewhere for vaccination.

Report vaccine fraud or abuse online to the NYS Attorney General (select "File a Complaint"). You can also call 833-VAX-SCAM (833-829-7226) or email

Immigration Status Does Not Matter

COVID-19 vaccines are available to people of all immigration statuses. You will not be asked about your immigration status at the vaccination site.

Getting vaccinated will not negatively impact you or your family’s immigration application.

Proof of Eligibility

You will need to bring proof of age, which can include:

  • Driver's license or other state ID
  • Valid U.S. or foreign passport
  • Birth certificate
  • Marriage certificate
  • Life insurance policy
  • Other document showing date of birth

If a minor does not have proof of age, their parent or guardian can attest to their age at the vaccination site.

Medical and Personal Information Protected

Your personal information is strictly protected. Your social security number is not collected or shared, nor is immigration status. Identification is only required for proof of age.

Basic information about you (such as your name, address, phone number, date of birth, race, ethnicity, vaccination date and vaccine received) will be shared with the Health Department as required by law. Strict laws are in place to make sure your information remains confidential.

The Health Department is required to send vaccination data to the CDC. Only people’s date of birth, ZIP code, race, ethnicity and gender are shared with the CDC. We will not share any other identifying information, including your name.

Prepare for Your Vaccination Visit

There is nothing special you need to do before getting vaccinated. Reschedule your appointment if you were diagnosed with COVID-19, have any symptoms of COVID-19, or were exposed to someone with COVID-19, in the last 10 days.

Remember to wear a mask and bring:

  • An insurance card if you have one
  • Proof of age (an ID or other document with birth date)
  • Completed and signed minor consent form (if you are younger than 18 years and are going without a parent or guardian, and if the site permits written consent)
  • Your vaccination card, if you are receiving a second, third or booster dose

Getting the Second Dose

The Pfizer and Moderna vaccines require two doses. Both doses should be of the same vaccine. If you received one dose of the Pfizer vaccine and you are between the ages of 12 to 64 and not immunocompromised, you should receive a second dose of the Pfizer vaccine eight weeks after your first dose. If you received one dose of the Moderna vaccine and you are between the ages of 12 to 64 and not immunocompromised, you should receive your second dose of the Moderna vaccine eight weeks after your first dose.

New research suggests that an eight-week interval between the first and second dose of these vaccines may increase the vaccines’ effectiveness and how long it protects against infection and hospitalization. It may also lower the chance of rare risks associated with the Pfizer and Moderna vaccines.

If you cannot get your second Pfizer or Moderna dose during the recommended interval, get it as soon as possible after. No matter how much time has passed, you should still get the second shot.

If you have already completed your two doses of Pfizer or Moderna with a three- or four-week interval between the first and second doses, you do not need to repeat your second dose.

The Johnson & Johnson vaccine requires only one dose.

Third Dose and Booster Shots

At least one vaccine booster shot is recommended for everyone 12 and older who is fully vaccinated. These shots boost your immunity from an initial vaccination series.

We recommend a booster shot for any adult who received the second dose of either the Pfizer or Moderna vaccine at least five months ago, or one dose of the Johnson & Johnson vaccine at least two months ago.

A second booster shot is also now available for:

  • All people who are 50 and older.
  • People who are 12 to 49 who are moderately or severely immunocompromised.
  • People who are 18 to 49 and received a primary dose and booster dose of the Johnson & Johnson vaccine.

If you are eligible, you can get your second booster shot four months after you received your first booster. The second booster must be either the Pfizer or Moderna vaccine. Review the CDC's guidance on how to decide if you should get a second booster.

For second booster shots, you must get either a Pfizer or Moderna vaccine. If you have questions, talk to your health care provider or call 212-COVID-19 (212-268-4319).

  • COVID-19 Vaccine Third Doses vs. Boosters (PDF)
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  • Third Doses for People with Weakened Immune System

    Separate from booster shots, some people who are moderately to severely immunocompromised (meaning they have a weakened immune system) should receive three doses of the Pfizer or Moderna COVID-19 vaccine, rather than the standard two-dose regimen.

    This shot is intended to help a small number of people who may not have had sufficient immunity from the first two shots. People who receive this shot may also be eligible to later receive a booster shot.

    Examples of conditions and treatments are:

    • Active treatment for cancer
    • Received an organ transplant and are taking immunosuppressive therapy
    • Received a stem cell transplant within the past two years
    • Moderate or severe primary immunodeficiency
    • Advanced or untreated HIV
    • Active treatment with a high dose of corticosteroids or other drugs that moderately or severely weaken your immune system

    This is not a complete list. If you have one of these conditions or are taking medicine that weaken your immune system, talk with your health care provider about getting a third dose.

    Vaccination Card

    After receiving your first shot, you will receive a card with your name, date of birth, the vaccine you received, and the place and date you received it. Your vaccination card is an important medical record. Keep it in a safe place and make a photocopy or take a picture just in case you lose it.

    Bring your vaccination card with you when you go for your second shot of the Pfizer or Moderna vaccine, or for a third dose or booster shot. If you forget to bring the card or lose it, the vaccination provider can look up your name to verify your prior dose or doses.

    If you lose your card, your health care provider can get and print proof of vaccination from the Citywide Immunization Registry. The registry contains records of people vaccinated in NYC, and some records of NYC residents vaccinated outside of the city.

    You can access your own vaccine record (and your minor children’s records) on My Vaccine Record.

    Common Side Effects

    Many people have side effects, which are normal signs that your body is building protection. Common side effects include soreness or swelling on the arm where you got the shot, headache, body aches, tiredness and fever. For the Pfizer and Moderna vaccines, get the second shot even if you have side effects after the first shot, unless your health care provider tells you not to.

    Side effects:

    • Usually are mild to moderate
    • Usually start within the first three days after vaccination and last for about one to two days after they begin
    • Are most common the day after vaccination
    • Are less common in older adults
    • Are more common after getting the second dose of the Pfizer or Moderna vaccines than after getting the first dose

    Managing Side Effects

    To reduce pain or swelling at the injection site, put a clean, cool, wet cloth over the area. Call your health care provider if:

    • You have any side effects that concern you or do not go away after a few days
    • The redness or soreness where you got the shot increases after 24 hours

    You can also talk to your provider about taking an over-the-counter medicine after vaccination to relieve pain or discomfort, such as acetaminophen (Tylenol) or ibuprofen (Advil).

    Reporting Side Effects

    It is helpful to report side effects so public health experts can track the effects of the vaccines. To complete health symptom check-ins and report side effects, you can sign up for the CDC's v-safe smartphone-based tool after vaccination. You can also report side effects online to the CDC and FDA’s Vaccine Adverse Event Reporting System (VAERS) or by calling 800-822-7967.

    Learn about these and other safety monitoring systems.

    Serious Side Effects

    The CDC has identified three serious side effects following COVID-19 vaccination. All are very rare. The CDC and other experts continue to recommend COVID-19 vaccination for everyone ages 5 and older. There is a low risk of these side effects and a much higher risk of serious illness from COVID-19.

    • Blood clots (Johnson & Johnson): There is a small risk of a rare type of blood clot with low blood platelet count in people who get the Johnson & Johnson vaccine. This condition is called thrombosis with thrombocytopenia (TTS). TTS following vaccination has occurred mainly in women younger than age 50, but also in men and older women.

    • Guillain-Barré syndrome (Johnson & Johnson): A small number of people who got the Johnson & Johnson vaccine have developed Guillain-Barré syndrome. The syndrome can cause muscle weakness, nerve damage and sometimes paralysis. Most people recover fully, but some have permanent damage.

    • Heart inflammation (Pfizer and Moderna): There is a small risk of inflammation of the heart (myocarditis) and surrounding tissue (pericarditis) reported in a small number of people who received the Moderna or Pfizer COVID-19 vaccine. Most cases have occurred in adolescent boys and young adults, are mild, and improve with treatment and rest.

    Allergic Reactions

    Serious allergic reactions to the vaccines are rare.

    Every person is observed for at least 15 minutes following the shot as a precaution. People with a history of severe allergic reactions (such as anaphylaxis) for any reason are observed for 30 minutes.

    Serious allergic reactions generally start within a few minutes to an hour of getting the shot.

    Signs of a severe allergic reaction can include:

    • Difficulty breathing
    • Swelling of the face and throat
    • Fast heartbeat
    • Severe rash all over the body
    • Dizziness
    • Weakness

    If you think you are having a severe allergic reaction, call 911 or go to the nearest hospital.

    After Vaccination

    COVID-19 Antibody Test Results

    Antibody tests that are currently available cannot test for immunity to COVID-19. They should not be used after COVID-19 vaccination to see if a person has developed immunity to COVID-19.

    Vaccine Breakthrough

    The vaccines are very effective at preventing COVID-19 infection. Most people who are vaccinated will not get COVID-19, but no vaccine is 100% effective. A small percentage of fully vaccinated people will become infected and get sick. This is called a breakthrough infection. For these people, the vaccine still provides strong protection against serious illness and death. People who are unvaccinated are much more likely to get COVID-19 and are at highest risk for severe illness.

    Anyone who is infected with the delta variant can spread the virus to others, regardless of whether they are vaccinated. The delta variant is much more contagious than the original virus. For this reason, even fully vaccinated people need to continue other COVID-19 precautions.

    Use of Face Masks and other COVID-19 Precautions

    After you are fully vaccinated, you can do many activities without wearing a mask or physical distancing. Outdoor activities are generally safer.

    You should keep your mask on in all public indoor settings, and in any setting where you do not know the vaccination status of the people around you. Also, you must follow the mask requirements of any place that you go, such as a business, school, public transportation or your workplace.

    If you have a condition or take medication that weakens your immune system, you may not be fully protected even if vaccinated. Talk to your doctor before stopping precautions.

    You no longer need to get tested regularly for COVID-19 once you are fully vaccinated. However, everyone with symptoms of COVID-19 should get tested, stay home and separate from others. This includes people who are vaccinated.

    People who are fully vaccinated should get tested if they have contact with someone who has COVID-19, or after returning from international travel.

    Learn more about the benefits of vaccination and the precautions you should continue to take:

    Vaccine Safety

    Clinical Trials

    The COVID-19 vaccines that are available in the U.S. were shown to be safe through clinical trials. These trials involved testing the vaccine on tens of thousands of volunteers. The process was monitored closely by the FDA and other organizations.

    To ensure the safety of the vaccines:

    • The FDA reviewed clinical trial plans to make sure they met the highest scientific and ethical standards.

    • Clinical trials were closely monitored by a data safety monitoring board made up of outside experts. These experts included medical personnel, ethicists, statisticians, patient advocates and others.

    • FDA scientists and medical professionals reviewed all available information to see if the vaccines should be authorized.

    Continued Safety Monitoring

    There are many safety monitoring systems in place to help ensure that any potential vaccine safety issues are quickly identified and investigated. These include:

    • VAERS. Health care providers must report serious health events following vaccination to a national reporting system, called Vaccine Adverse Event Reporting System (VAERS), managed by the CDC and FDA. People can also self-report side effects or other reactions to VAERS online or by calling 800-822-7967

    • v-safe. The CDC created an app called v-safe that people can use to report reactions to a COVID-19 vaccine. The tool helps the CDC track side effects to learn more about their frequency and severity.

    • Vaccine Safety Datalink. This is a collaboration among nine health care organizations and the CDC’s Immunization Safety Office. The health care organizations share electronic health data about vaccines given and any medical problems diagnosed.

    • Post-Licensure Rapid Immunization Safety Monitoring (PRISM). Checks information from health plans and immunization registries to find and check out rare health events.

    • Clinical Immunization Safety Assessment Project. Conducts studies to learn about vaccine safety and helps health care providers who have vaccine safety questions about specific patients.

    Not all adverse event reports mean there is a problem with the safety of vaccines. VAERS detects patterns of health events, also known as safety signals. If VAERS finds a safety signal, experts can see if there is a connection between the health events and a vaccine. VAERS contains all reports submitted, no matter how accurate or likely it is that the events are related to the vaccine. VAERS reports alone are not used to judge the safety of a vaccine.

    Long-Term Safety

    Serious side effects from vaccines typically show up within a few days, and almost always within two months. Reactions after that are very unlikely.

    The vaccine clinical trial participants have been monitored for more than two months and continue to be monitored. Also, millions of people have received the vaccines safely and no long-term negative effects have been identified.


    Claims linking COVID-19 vaccines to fertility problems are unfounded and have no scientific evidence supporting them. The CDC says it is safe for people who want to have a child to get a COVID-19 vaccine and recommends that they get vaccinated.

    Vaccines Cannot Cause COVID-19

    None of the vaccines available in the U.S. contain the virus that causes COVID-19. It is not possible to get COVID-19 from the vaccines.

    Vaccines Cannot Change Your DNA

    The COVID-19 vaccines used in the U.S. contain genetic material that tells the body’s cells to start building protection against the virus. However, the material never interacts with your DNA. This means the genetic material in the vaccines cannot affect your DNA in any way.

    Vaccine Ingredients and How They Work

    How the Pfizer and Moderna Vaccines Work

    Both the Pfizer and Moderna vaccines are messenger RNA (mRNA) vaccines. mRNA is a molecule that contains the blueprint for making proteins. These are the first mRNA vaccines to be available, but the technology has been studied for over 30 years.

    Here is how mRNA vaccines work:

    1. The mRNA molecules enter the body with instructions on how to make a protein that is part of the virus that causes COVID-19.

    2. The proteins produced trigger the body to make antibodies (special proteins that fight against a specific infection) and other defenses.

    3. The mRNA is then broken down and destroyed by the body.

    4. If a person is exposed to COVID-19 after they were vaccinated, the body will be able to recognize the virus and produce antibodies and other defenses to fight it.

    mRNA is similar to an email that gets sent to your body with instructions on how to identify and destroy the virus. Your body uses those instructions and then deletes the email completely.

    How the Johnson & Johnson Vaccine Works

    The Johnson & Johnson vaccine is an adenovirus vector vaccine. Johnson & Johnson has been researching adenovirus vector vaccines for other infections for decades. The company’s Ebola vaccine is also an adenovirus vector vaccine and is already in use.

    The Johnson & Johnson vaccine works similarly to the Pfizer and Moderna mRNA vaccines. However, it uses a different type of messenger to deliver instructions for making an immune response. Scientists took a gene from the virus that causes COVID-19 and put the gene into an adenovirus. The adenovirus used in this vaccine causes the common cold, but the virus was modified so that it cannot multiply in humans or cause infection.

    Here is how the Johnson & Johnson vaccine works:

    1. When the vaccine enters your body, the adenovirus carries a gene from the coronavirus into human cells. Your body then makes a COVID-19 protein, but not the virus itself.

    2. The proteins that are produced trigger your body to make antibodies, special proteins that fight against a specific infection.

    3. If you are exposed to COVID-19 after you are vaccinated, your body will recognize the virus and your immune system will be ready to fight it.

    Vaccine Ingredients

    The Pfizer and Moderna vaccines contain the following types of ingredients:

    • Lipids: Lipids are molecules of fat that do not dissolve in water. They surround the mRNA, protecting it so it does not break down before it gets into your cells. One example of a lipid included is polyethylene glycol.

    • Salts, acetic acid and amines: These are all used to protect your cells by keeping the pH (acidity level) of the vaccine similar to the pH in your body. The Pfizer vaccine contains four salts, including table salt. The Moderna vaccine contains acetic acid (the kind of acid in vinegar), one salt and two organic compounds derived from ammonia known as amines.

    • Sugar: Sugar helps keep the lipids from sticking to each other or to the sides of the vaccine vial.

    The Johnson & Johnson vaccine contains the following types of ingredients:

    • Stabilizers: Salts, alcohol, polysorbate 80 and hydrochloric acid.
    • Manufacturing biproducts: Amino acids.

    The vaccines do not contain:

    • Antibiotics
    • Blood products
    • Fetal tissue or human cells
    • Gelatin
    • Gluten
    • Mercury
    • Microchips
    • Pork or other animal products
    • The virus that causes COVID-19

    See a full list of ingredients for the Pfizer vaccine (PDF), the Moderna vaccine (PDF), and the Johnson & Johnson vaccine.

    Herd Immunity

    Herd immunity is when enough people in a population have immunity (protection) against a contagious disease that the disease is unlikely to spread. As a result, even people who are not vaccinated are at lower risk for infection. The percent of the population that needs to have immunity to reach herd immunity is different for different diseases.

    There is still transmission of COVID-19 in New York City and elsewhere. Experts agree we have not achieved herd immunity. Every eligible person should get vaccinated to protect themselves and others.

    New Variants/Strains of the Virus

    It is normal for a virus to mutate (change) over time and for new variants to occur. Several variants of the virus that cause COVID-19 have been identified. Some of these variants spread more easily and quickly than others and may cause more severe disease. This may lead to more COVID-19 cases, hospitalizations and deaths. The presence of these variants makes it even more important to get vaccinated.

    All three vaccines protect against current variants, including the delta variant. The vaccines reduce the risk of getting COVID-19 and are still very effective at protecting against severe illness, hospitalization and death from current variants.

    Medical History and Clinical Considerations


    You can get vaccinated if you have a history of allergic reactions to food (including eggs), antibiotics or other medicine that you take by mouth, pet dander, venom, dust mites, pollen, mold, cigarette smoke, or latex. You can also get vaccinated if you have a family history of allergic reactions.

    Talk to your health care provider before getting vaccinated if you have ever had a severe or immediate allergic reaction to:

    • A COVID-19 vaccine
    • An ingredient in a COVID-19 vaccine
    • Any other vaccine or injectable medicine

    Currently Sick with COVID-19

    If you have recently tested positive for COVID-19 or have symptoms of COVID-19, you should wait to get vaccinated until you have completed isolation to avoid exposing others to COVID-19.

    Previously Sick with COVID-19

    The CDC and other experts recommend getting vaccinated even if you already had COVID-19. Getting vaccinated is a safe way to help strengthen your immune system and lower your chance of getting COVID-19 again. A vaccine may also give you better protection against new, more contagious variants of the virus, like the delta variant.

    There is no evidence that having had COVID-19 will cause a person to have a bad reaction to the vaccines.

    Monoclonal Antibody Treatment

    Monoclonal antibody treatment is a type of treatment prescribed by a doctor for people who have tested positive for COVID-19.

    If you have had monoclonal antibody treatment, you should wait 90 days after your treatment to get vaccinated.

    If you have been vaccinated and then later developed COVID-19, you can still get monoclonal antibody treatment if you are otherwise eligible.

    Recent Exposure to COVID-19

    If you were recently in close contact with someone who has COVID-19 (within 6 feet for at least 15 minutes over a 24-hour period), you should wait to get vaccinated until after you have quarantined for 10 days since you were last exposed.

    If you are exposed to someone with COVID-19 between your first and second doses of the Pfizer or Moderna vaccine, you should still get your second dose. Postpone getting your second dose if it is during your quarantine period. You should get your second dose as soon as possible after that.

    Other Vaccinations

    You can get your COVID-19 vaccine before, after or at the same time as you receive any other vaccine. Everybody should get both a flu vaccine (before or during flu season) and a COVID-19 vaccine.

    COVID-19 Vaccinations in Clinical Trials

    Participants in the U.S.-based AstraZeneca and Novavax COVID-19 vaccine clinical trials can be considered fully vaccinated two weeks after they complete the vaccine series. They must be able to confirm they received the “active” vaccine, and a not placebo.

    COVID-19 Vaccines From Outside the U.S.

    People coming to the U.S. from other countries may be partially or fully vaccinated with vaccines that are not authorized or approved by the FDA.

    If you have received all recommended doses of one or more COVID-19 vaccines that are authorized or approved by the FDA or authorized by the World Health Organization (WHO), you are considered fully vaccinated.

    If you have not received the single-dose Johnson & Johnson vaccine or two doses of one or more vaccines authorized or approved by the FDA or WHO, you can get a complete, FDA-authorized or approved COVID-19 vaccine series. You must wait at least 28 days from your last dose of the other COVID-19 vaccine.

    If you received all or some of the recommended doses of a COVID-19 vaccine that is not listed for emergency use by WHO, you can get a complete, FDA-authorized or approved COVID-19 vaccine series. You must wait at least 28 days from your last dose of the other COVID-19 vaccine.

    Talk to your provider if you have questions.

    Pregnant or Breastfeeding

    The CDC, the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) strongly recommend that all people who are pregnant or breastfeeding be vaccinated against COVID-19. This recommendation is based on available evidence about vaccine safety for people who are pregnant and breastfeeding and the risks of getting COVID-19. This includes the increased risks of the more contagious and dangerous delta variant of the virus. Early data from safety monitoring systems did not identify any safety concerns from the vaccines for pregnant people or their babies.

    People who are pregnant or breastfeeding can be vaccinated in any setting, such as City-run vaccination sites, pharmacies or their doctor’s office. There is no recommendation for pregnancy testing prior to receiving a COVID-19 vaccine.

    Menstrual Cycle

    Menstrual cycle changes can be caused by many factors, like stress and changes in sleep, diet, environment and lifestyle, which are common during the COVID-19 pandemic. More research will be carried out to see if there is a link between COVID-19 vaccination and temporary menstrual changes. However, experts agree you do not need to plan getting vaccinated around your menstrual cycle and the vaccine can be given safely while menstruating.


    If you are due for a mammogram and have been recently vaccinated for COVID-19, ask your doctor how long you should wait after vaccination to get your mammogram.

    The COVID-19 vaccine can cause swelling in the lymph nodes in the underarm near the injection location. This swelling is a normal sign that your body is building protection against COVID-19, but it could cause a false reading on a mammogram. Some experts recommend getting your mammogram before being vaccinated or delaying a routine mammogram until four to six weeks after you get your vaccine. Talk to your provider if you have questions.

    People who are Immunocompromised

    The CDC recommends that people with immunocompromising conditions be vaccinated.

    People who are immunocompromised are at increased risk for severe COVID-19 illness. The vaccines available in the U.S. do not contain the live virus and can safely be given to people who are immunocompromised. This includes people with HIV or other immunocompromising conditions and people who take medications that weaken their immune system.

    A third dose of vaccine is recommended for people who are moderately to severely immunocompromised (PDF) and received the Pfizer or Moderna vaccine.

    If you have a condition or take medication that weakens your immune system, you may not be fully protected even if vaccinated. Talk to your health care provider before stopping precautions, such as wearing a mask and physical distancing.

    Guillain-Barré syndrome

    There is a small risk of Guillain-Barré syndrome (GBS) following receipt of the Johnson & Johnson vaccine. This association has not been seen with the Pfizer and Moderna COVID-19 vaccines.

    People with a history of GBS can receive any of the FDA-authorized or approved COVID-19 vaccines and can discuss with their provider when choosing a vaccine.

    Bell's Palsy

    People who have previously had Bell’s palsy (facial paralysis) may receive any of the FDA-authorized or approved vaccines.

    A small number of cases of Bell’s palsy were reported following vaccination in the COVID-19 vaccine clinical trials. However, the FDA does not consider these to be more than the rate expected in the general population. They have not concluded these cases were caused by vaccination. The CDC and other experts continue to closely monitor safety data and will investigate if a potential safety issue is identified.

    People With Dermal Fillers

    Infrequently, people who have received dermal fillers have experienced swelling at or near the site of filler injection (usually face or lips) following receipt of the Pfizer or Moderna vaccine. This has not been seen in recipients of the Johnson & Johnson vaccine. The swelling appears to be temporary and resolves with medical treatment, including corticosteroid therapy.

    People who have received injectable dermal fillers can receive any of the FDA-authorized or approved vaccines. They should contact their health care provider for evaluation if they experience swelling at or near a dermal filler site following vaccination.

    Other Medical Conditions and Medicines

    Several medical conditions put people at increased risk for serious illness if they get COVID-19, making it especially important to get a COVID-19 vaccine. Many people who were part of the clinical trials had underlying health conditions, and the vaccine was safe and effective for them. Many millions of people in the general public with underlying medical conditions have been vaccinated. People with any medical condition can get vaccinated, unless they have had certain allergic reactions to a COVID-19 vaccine or its ingredients.

    Also, people do not need to stop taking any type of prescription medicine when they receive a COVID-19 vaccination.

    If you have concerns about an underlying medical condition or medicine, discuss vaccination with your health care provider.

    Vaccine Development, Authorization and Approval

    Development and Testing

    The COVID-19 vaccines followed the same development steps as other vaccines: They were developed and tested in a laboratory and then went through clinical trials closely monitored by the FDA.

    Clinical trials involve testing the vaccine in people to see if it is safe and effective. The COVID-19 vaccines were each tested on tens of thousands of people of different genders, ages, races and ethnicities who volunteered to be part of the clinical trials.

    Emergency Use Authorization

    In an emergency, the FDA may allow vaccines, as well as tests and treatments, to be used by granting an Emergency Use Authorization (EUA). The Pfizer, Moderna and Johnson & Johnson vaccines have each been granted an EUA.

    All vaccines granted an EUA must go through the same clinical trials as all other vaccines. The FDA may grant an EUA only if evidence strongly suggests the benefits of getting the vaccine outweigh any risks to patients.


    The FDA expects manufacturers whose COVID-19 vaccines are authorized under an EUA to continue clinical trials to get additional safety and effectiveness information for a longer period of time, and to apply for approval (licensure).

    The Pfizer vaccine has now received licensure for people ages 16 and older (marketed under the name Comirnaty). Use of the vaccine in people ages 5 to 15 is still under the EUA.

    Moderna has applied for licensure and Johnson & Johnson, which became available later, is still collecting additional data.

    Additional Resources