COVID-19 Vaccination Information and Resources

Covid Vaccine Information

Getting vaccinated—including getting a booster shot—is the best way to protect yourself, your loved ones, and your community from COVID-19.

The Food and Drug Administration has granted full approval to the Pfizer-BioNTech COVID-19 vaccine for people ages 12 and older, and to the Moderna vaccine for those 18 and older. Children younger than that may receive the Pfizer-BioNTech or Moderna vaccines under emergency use authorization (EUA) if they are at least six months old. Also under EUA, the Johnson & Johnson and Novavax vaccines are available to those 18 and older.

The mRNA vaccines made by Pfizer-BioNTech and Moderna require two shots, normally given about three to four weeks apart. People who are considered severely immunocompromised are recommended to get a third shot as part of their primary series.

The FDA has now authorized updated booster shots that offer increased protection against newer versions of the virus. For continued protection, people ages 5 and up should get one of these booster shots two months after their second dose or most recent booster. More information about these new “bivalent” booster shots can be found on Mount Sinai Today.

Five Things to Know About Vaccines
(Updated 12/9/22)

Vaccination Appointments

Patients ages 12 and up, please visit this link to make an appointment for a first dose or booster shot of the Pfizer-BioNTech vaccine at Mount Sinai. (Appointments for second doses will be made at the time you receive the first dose.)

Patients ages 5-11 can be scheduled for vaccination appointments through their doctor's office.

You can also check the New York State, New York City, New Jersey, or Connecticut websites for other locations that offer appointments or walk-in vaccination.

Patients ages 16 to 18 need parental/guardian consent for vaccination. Patients ages 5 to 15 must be accompanied by a parent or guardian.

People who are age 5 and older and who are moderately or severely immunocompromised are eligible for additional doses of an mRNA vaccine (Pfizer-BioNTech for ages 5 and up; Moderna only if 18 or over) as part of their primary series. This includes many people who are getting treatment for cancer, have had organ transplants, or receive treatments that weaken their immune systems. In addition, if you have received a bone marrow transplant or CAR-T therapy, you may need to repeat your vaccine series if you were vaccinated before receiving these treatments. If you are in one of these categories, please make an appointment through your doctor’s office.

Everyone receiving a booster shot will need to bring their original vaccine card with them to their appointment.

COVID-19 Vaccine Myths

There are a lot of myths on the internet about COVID-19 vaccines. Mount Sinai is working with a company called NewsGuard to provide the most accurate information. If you’ve heard something that sounds questionable and want to know if it’s true or not, you can look it up in NewsGuard’s report on top COVID-19 vaccine myths.

Frequently Asked Questions About the COVID-19 Vaccine

Below are some helpful answers to the most frequently asked questions we receive about the COVID-19 vaccines.

In addition, a panel of Mount Sinai experts in infectious disease and clinical care have addressed some of the most common concerns about COVID-19 and vaccination in video roundtable discussions. They can be viewed here:

How do the vaccines protect me from COVID-19?

Getting vaccinated–including booster shots–is the best way to protect yourself from hospitalization and death from COVID-19.

Vaccines expose us to pieces of either a bacteria or a virus. Our body’s immune system responds by making antibodies that fight against those pieces. The goal is that if we are exposed to the real bacteria or virus in the future, our body will recognize it and use the antibodies to fight it off.

The mRNA vaccines—made by Pfizer and Moderna—are the most effective at preventing serious illness and death from COVID-19. They do not contain any part of the COVID-19 virus. They contain instructions for your cells to follow. These instructions (called mRNA) tell your cells to make a piece of the COVID-19 virus, called the spike protein. Once your cells make the spike protein, your immune system will make antibodies that fight the COVID-19 virus and protect you from getting sick. The newest versions of these vaccines contain instructions for both the original spike protein and newer variants, offering additional protection.

The Johnson & Johnson vaccine also instructs your cells to make the COVID-19 spike protein themselves. Rather than using mRNA technology, however, it delivers those instructions by using a harmless adenovirus, similar to a common cold virus. Remember: if you have received a Johnson & Johnson vaccine, you should follow up with an mRNA booster two months later.

The Novavax vaccine delivers the spike protein directly into your body, rather than teaching your own cells to make it. This is a more traditional approach that is also used for other vaccines, like the yearly flu shot. (Updated 9/9/22)

How do I know a vaccine is safe?

All vaccines are closely studied and tested, including the vaccines for COVID-19. The FDA reviews all vaccines for safety before allowing them onto the market. Once they are on the market, we continue to monitor them closely. If any concerns arise, the FDA quickly responds and updates its guidelines and recommendations.

In New York State, the Governor’s Clinical Advisory Task Force, which includes highly respected scientists like Adolfo García-Sastre, PhD, Irene and Dr. Arthur M. Fishberg Professor of Medicine at the Icahn School of Medicine at Mount Sinai, also offers an independent opinion about each vaccine’s safety and efficacy.

The Advisory Committee for Immunization Practices (ACIP), a group of medical and public health experts that advises the CDC, also assesses the safety and efficacy of vaccines. They helped to develop the recommendations on COVID-19 vaccine use. (Updated 1/7/22)

Should I take the vaccine if I am pregnant or considering pregnancy, or if I am breastfeeding?

Pregnant and breastfeeding persons and those who are considering pregnancy are encouraged to speak to their health care providers about the potential benefit of vaccination, especially if they are a health care worker or an essential worker, or have underlying medical conditions.

New York State Department of Health (NYSDOH): Protect Yourself, Your Family, and Your Baby

Can children get vaccinated?

Yes. The Pfizer-BioNTech and Moderna vaccines have been authorized for children as young as six months old, and the new “bivalent” boosters are available for children five years and older.

None of the 1,178 children ages 6-23 months, and 1,838 children ages 2-4 years, who received three doses of the Pfizer vaccine in a clinical trial experienced a severe case of COVID-19. Clinical trials of this vaccine in older children took place before the rise of the Omicron family of variants, but the CDC reported recently that vaccinated adolescents were far less likely than unvaccinated ones to be admitted to the hospital for COVID-19 and to need intensive care once there.

Moderna conducted clinical trials in children ages 6-23 months, 2-5 years, 6-11 years, and 12-17 years. No child in any of these age groups reported severe COVID-19 during the trial period. (Updated 10/14/22)

If I already had COVID-19, should I get vaccinated?

It is safe and recommended to get vaccinated as soon as you have recovered and are no longer requiring isolation (usually 10 days after the symptoms started). If you have been treated for COVID-19 infection with monoclonal antibodies or convalescent plasma in the past 90 days, you should plan to get vaccinated after the recommended 90-day waiting period. (Updated 8/31/21)

What do we know about side effects from the vaccines?

Like all vaccines, the COVID-19 vaccines can cause short-term side effects. These side effects are normal signs that your body is building up its protection against COVID-19. Side effects usually go away within a day or two and can be treated with over-the-counter pain medications.

The following side effects are common for the Moderna, Pfizer, and Johnson & Johnson vaccines:

  • Pain in the arm where you received your shot
  • Tiredness
  • Headache
  • Muscle pain
  • Chills
  • Joint pain
  • Fever

If you experience side effects that are worrying or do not seem to go away after a few days, please tell your health care provider.

Serious side effects are extremely rare. Nearly 8 billion doses of the COVID-19 vaccines have been given worldwide, including more than 450 million in the United States. The safety of the vaccines is closely monitored—in fact, the COVID-19 vaccines are the most closely monitored vaccines in history.

There have been reports of people developing inflammation of the heart muscle (myocarditis) or the lining of the heart (pericarditis) after vaccination. These reports remain rare in the setting of millions of doses of vaccines being given. The conditions typically occur within a week of receiving the second dose of the Pfizer or Moderna vaccines, and they are more common in young males. It is important to remember that the risk of developing myocarditis or pericarditis from COVID-19 infection is greater than the risk from vaccination. Also, the cases from vaccination have been milder than cases from COVID-19 infection.

The CDC and the American Academy of Pediatrics continue to recommend COVID-19 vaccination as the best form of protection for adolescents.

The Centers for Disease Control and Prevention recommends that mRNA vaccines be used instead of the Johnson & Johnson vaccine. A rare and serious type of blood clot has been reported in a small number of patients who received the Johnson & Johnson (Janssen) vaccine. Women ages 18-49, especially, should be aware of the rare but increased risk of this side effect. This rare blot clot has not been associated with the Moderna or Pfizer vaccines. The FDA advises that people who have received the Johnson & Johnson vaccine should contact their health care provider if they develop severe headache, abdominal pain, leg pain, or shortness of breath within three weeks after vaccination.

For more information about COVID-19 side effects, please visit: (Updated 1/7/22)

How many shots do I need?

The Pfizer, Moderna, and Novavax vaccines require two doses, given about three to four weeks apart. It is very important that you get both doses at the recommended times. The Johnson & Johnson vaccine requires only one dose.

The CDC also recommends that people ages 5 and over get a booster shot two months after their initial dose(s) or their most recent booster.

In addition, people who are age 5 and older and who are moderately or severely immunocompromised are eligible for an additional (third) dose of an mRNA vaccine (Pfizer-BioNTech for ages 5 and up; Moderna only if 18 or over) as part of their primary series. This includes many people who are getting treatment for cancer, have had organ transplants, or receive treatments that weaken their immune systems. In addition, if you have received a bone marrow transplant or CAR-T therapy, you may need to repeat your vaccine series if you were vaccinated before receiving these treatments. (Updated 10/14/22)

How long should I wait between doses of an mRNA vaccine?

The general recommended interval between your first and second doses of mRNA vaccines is three weeks for the Pfizer/BioNTech and four weeks for the Moderna vaccine. However, the CDC says that people ages 12 through 64 years, and especially males ages 12 through 39 years, may consider getting the second dose eight weeks after the first dose.

People ages 5 and up are recommended to get a booster dose at least two months after their second dose or most recent previous booster. (Updated: 10/14/22)

In what cases should people wait longer for a second dose of mRNA vaccine?

Some patients, especially healthy males between the ages of 12 and 39, should consider extending the interval between the first and second dose of the mRNA vaccines to up to eight weeks, according to the CDC. Extending the interval between the doses of mRNA vaccines may improve immune response and decrease the rate of myocarditis. Important note: This should be a shared decision between you and your doctor and should take into account the level of COVID-19 transmission in your community. (Updated 3/15/22)

I am immunocompromised and received three doses already. When can I get my booster (fourth) dose?

Immunocompromised people who have received a primary series of three doses can receive a booster dose as early as three months after their third dose of an mRNA vaccine. (Updated 3/15/22)

How much are the COVID-19 vaccines?

The COVID-19 vaccines are free for everyone. You do not need health insurance to get vaccinated. If you do have insurance, please bring your card with you to your appointment. Your insurance may be billed but you will not be charged a co-pay or any other fees. (Updated 3/10/22)

If I got vaccinated outside the United States with a vaccine that is not used here, do I need to get revaccinated?

If you got vaccinated outside the United States, you may have been given a vaccine that has not received emergency use authorization from the U.S. Food and Drug Administration (FDA). As of July 2022, only the Pfizer-BioNTech, Moderna, Johnson & Johnson (Janssen), and Novavax vaccines have been authorized by the FDA.

If you received a different vaccine, here is guidance from the CDC and the New York City Department of Health and Mental Hygiene for what you should do:

  • If you received all recommended doses of a COVID-19 vaccine that is authorized for emergency use by the World Health Organization (WHO), you do not need to be vaccinated again. As of May 2022, the WHO list of authorized vaccines includes the AstraZeneca, Novavax, Covishield and Covovax (India), and Sinovac, CanSinoBio, and Sinopharm (China) vaccines.
  • If you did not receive the full recommended number of doses of a WHO-listed COVID-19 vaccine, you may want to be revaccinated with the full recommended doses of a COVID-19 vaccine authorized by the FDA (i.e., two doses of the Pfizer or Moderna vaccines or a single dose of the Johnson & Johnson vaccine). If you received a vaccine that is not listed for emergency use by WHO, you may want to be revaccinated with an FDA-authorized COVID-19 vaccine.
  • You should wait at least 28 days between your last dose of the non-U.S. vaccine and your first dose in the United States.

(Updated 7/21/22)

Should I get my antibodies checked after getting my COVID-19 vaccination?

No. COVID-19 antibody tests offered by commercial laboratories are designed to measure immunity resulting from infection, not from vaccination. These tests look for antibodies that are different from those made by current vaccines, so you won’t get a true picture of your protection.

And even if you have antibodies from a previous infection, those test results may not mean you are immune. On May 19, 2021, the FDA issued a safety warning to the public stating that results from COVID-19 antibody tests should not be used to measure the level of protection from COVID-19 at any time, especially after COVID-19 vaccination.

The CDC recommends that people who have had only one dose of a two-dose COVID-19 vaccine series get the second dose regardless of the results of antibody testing. Likewise, people who are fully vaccinated against COVID-19 do not need any additional doses of COVID-19 vaccine if they have negative or low antibody test results. (Updated 6/11/21)

Should I take over-the-counter pain medications before or after my vaccination?

If you regularly take aspirin, acetaminophen (e.g., Tylenol), or ibuprofen (e.g., Motrin, Advil) for other medical conditions, continue to do so as directed by your physician or as needed. Otherwise, do not take these medications before getting vaccinated. Taking over-the-counter medications like these before receiving a vaccine may decrease your immune response to the vaccine, making it less effective. After the vaccination, you can take an over-the-counter medication as needed to address side effects from the vaccine.

What Is an Emergency Use Authorization?

In the United States, vaccines must be approved by the Food and Drug Administration (FDA) before they can be used. The FDA bases its decision on data from clinical trials. In a clinical trial, the vaccine is given to volunteers—sometimes tens of thousands of them—while others get a placebo, meaning an injection that doesn’t contain any vaccine. Scientists observe whether the people who got the vaccine get fewer cases of the disease than those who got the placebo. This means that the vaccine appears to work in those people; this is called the vaccine’s “efficacy.” The scientists also watch out for unexpected side effects that the vaccine might have caused. This is called the vaccine’s “safety.”

If the clinical trial data shows enough evidence of efficacy and safety, the FDA will approve the vaccine and license it for use in the United States.

Sometimes, the FDA will allow a medical product that has not yet been fully approved to be used in an emergency to diagnose, treat, or prevent a serious illness. This is called “emergency use authorization” or “EUA”.

An EUA may be issued when the FDA determines that the product “may be effective” against the disease based on all the available scientific evidence. This is a lower standard than required for full approval of a product; it uses early data gathered from clinical trials.

More information on EUAs is available from the FDA website.

Will taking this vaccine give me COVID-19?

No. It is NOT possible to get COVID-19 from the vaccines made by Pfizer or Moderna, or any of the other vaccines in advanced clinical trials.

Should I take the vaccine if I have severe allergies?

Do not get the Pfizer, Moderna, or Johnson & Johnson COVID-19 vaccines if you have had a severe allergic reaction (i.e., anaphylaxis) to vaccines or the components of that vaccine. If you have a history of severe medication allergies, please discuss with your health care provider. (Updated 3/1/21)

Do the clinical trials for COVID-19 vaccines include people from the most affected groups?

Yes. While vaccines work the same in people of different races or ethnicities, it is important to make sure vaccines are tested in diverse population groups before they are released. The phase 3 clinical trials conducted by Pfizer and Moderna included significant numbers of participants from the population groups most at risk for COVID-19.

In Pfizer’s U.S. trial, 13.1 percent of participants are Hispanic/Latinx, 10.1 percent are Black, 5.5 percent are Asian American, and 1 percent are Native American. About 45 percent of U.S. participants are 56 to 85 years of age.

For comparison, in the most recent estimates by the U.S. Census Bureau, across the United States population, 18.4 percent of people are Hispanic/Latinx, 12.8 percent are Black, 5.7 percent are Asian American, and 0.9 percent are Native American. The Census uses slightly different age groups than the drug companies, but says that 27.4% of Americans are between ages 55 and 84.

Of the patients in Moderna’s trial, 9.7 percent identified as Black or African American, 20 percent as Hispanic/Latinx, 4.7 percent as Asian, and 0.8 percent as Native American. Also, 25.3 percent were over the age of 65 (compared to 16.5 percent in the general population), and 22.3 percent had at least one high-risk chronic disease, such as diabetes, severe obesity, or cardiac disease.

In Johnson & Johnson’s worldwide trials, 59 percent of patients were white, 45 percent were Hispanic and/or Latinx, and 19 percent were Black or African American. In their trial in the United States, 74 percent were white, 15 percent Hispanic/Latinx, and 13 percent Black or African American. Forty-one percent of participants in the Johnson & Johnson study had health conditions associated with an increased risk for severe COVID-19.

Researchers regularly test new medicines in a diverse population. (Updated 11/22/21)

How do I know if the information I’m reading about vaccines online is accurate?

There is a lot of information on the internet about vaccines, and it can be difficult to know which sites to trust. Mount Sinai is providing a tool called NewsGuard, which is a browser extension (this adds features and functions to a browser) you can download that will help determine which information about vaccines and other health topics is accurate.

Will the COVID-19 vaccine affect my period?

The menstrual cycle begins on the first day of a period, and the average cycle is 28 days. COVID-19 vaccination is linked with a temporary increase in this cycle of about one day on average, though not an increase in days of menses or bleeding, the National Institutes of Health says, citing a large international study. These changes after vaccination appear to be small and within the normal range of variation, the NIH says. Changes in the menstrual cycle are common and have a variety of causes. These may include stress, weight gain, changes in physical activity, and underlying medical conditions. Susan S. Khalil, MD, Assistant Professor of Obstetrics, Gynecology and Reproductive Science at the Icahn School of Medicine at Mount Sinai, encourages patients who notice irregularities in their cycle to contact a gynecologist. (Updated 10/11/22)

Learn More

Coronavirus (COVID-19) Facts and Resources
Frequently Asked Questions (FAQs)
Preventive measures for Flu & COVID-19 (English)
Preventive measures for Flu & COVID-19 (Spanish)
How to Wash Your Hands the Right Way (Video)

CDC Resources

CDC Website

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