COVID-19 Vaccine Frequently Asked Questions

Read answers to commonly asked questions about COVID-19 vaccines.

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Safety and Eligibility Questions

Vaccine Location Questions

Other Vaccine Questions

Johnson & Johnson Vaccine Questions

Safety and Eligibility Questions

Are the COVID-19 vaccines safe?

There are many strict protections in place and steps taken during vaccine development to ensure that any vaccine authorized for use is proven to be safe and effective. Vaccine developers are required to go through a rigorous, multi-stage process including large (phase III) trials that involve tens of thousands of participants.

More than 70,000 people from diverse backgrounds and ethnicities participated in the COVID-19 vaccine clinical trials. Clinical trials for the three vaccines included White, Hispanic/Latino, Black, Asian, and other races/ethnicities.

After the clinical trials show that the vaccines are safe and effective, a series of independent reviews and evidence is required to demonstrate efficacy and safety. The FDA is responsible for making sure that FDA-authorized or approved COVID-19 vaccines are safe and effective. Duke experts in vaccine science reviewed all available safety and efficacy data for any authorized vaccine to ensure the evidence supports its broad use.

What ingredients are in the COVID-19 vaccines?

The Pfizer vaccine and the Moderna vaccine use mRNA to instruct the cells in your body to make a harmless piece of the “spike protein” found on the surface of COVID-19. Your immune system is tricked into thinking this is a virus and makes antibodies.  A live virus is not included in the vaccine. Your body destroys the mRNA and gets rid of it. It doesn’t stay in your body or alter any DNA. The other ingredients in the Pfizer and Moderna vaccines are salt, sugar, and fat.

The Johnson & Johnson COVID-19 vaccine uses a harmless inactivated cold virus as the carrier for the genetic material that codes for a piece of the “spike protein” of COVID-19 to help the body build an immune response against the coronavirus that causes COVID-19. These types of vaccines are generally safe for large populations of people.

None of the vaccines contain eggs, preservatives, fetal tissue, stem cells, mercury, or latex.

Are the vaccines safe for children?

The Pfizer vaccine is the only vaccine currently approved by the FDA and CDC for use in teens ages 12 to 17. Clinical trials of the COVID-19 vaccines determined the Pfizer vaccine was safe and highly effective in this age group. Studies are completed for the Moderna vaccine and are pending FDA review. Work is underway to determine if the J&J vaccine can also be administered safely and effectively in this age group. Trials are also being conducted to determine the safety and effectiveness of the vaccines in younger age groups. More information will be available from the vaccine manufacturers as these trials progress.

Are the vaccines safe for pregnant people?

The approved COVID-19 vaccines have not been studied in pregnancy. However, we know that pregnant people are at an increased risk for complications from COVID-19. That's why we encourage all pregnant people to ask questions and discuss their concerns with their care providers.

So far, there have been no significant adverse events seen in pregnant women receiving the Pfizer or Moderna vaccines. 

Should I get the vaccine if I am breastfeeding?

The approved COVID-19 vaccines were not studied in people who are breastfeeding. However, according to the Centers for Disease Control, there is no data indicating that the vaccines would be a risk to infants who are breastfeeding. If you are breastfeeding, discuss your concerns with your care providers. Duke Health will offer breastfeeding people the option to get vaccinated in accordance with North Carolina guidelines for vaccine distribution.

Can the COVID-19 vaccine make me infertile/sterile?

No. There is no evidence to suggest the vaccines cause infertility or affects your ability to become pregnant. A rumor on the Internet claims a protein created by the body after vaccination is similar to a protein that is needed for placental formation. This is not true. The proteins are not similar nor do they impact fertility or affect a pregnancy. The vaccine manufacturers are monitoring people in the clinical trials who became pregnant.

Do the vaccines cause side effects?

There is a potential for injection site reactions (redness, swelling, and pain) as well as fever, fatigue, headache, chills, nausea, vomiting, diarrhea, muscle pain, and/or joint pain. These are adverse reactions commonly seen with other vaccines. There may be other reactions that are not currently known. If you are receiving a two-dose vaccine, it is important that you receive the second dose to ensure the vaccine is effective, even if you experience side effects after the first dose.

If you have a severe allergic reaction following the first dose of a two-dose vaccine course, such as anaphylaxis, you should not receive the second dose. The incidence of this occurring is low, about one in six per million doses.

Should I get the vaccine if I have allergies?

You can receive the vaccine if you have allergies to injectable medicines, antibiotics, pets, environmental substances, or foods. The three approved COVID-19 vaccines do not contain egg protein, and are safe for people who have egg allergies. If you have questions about allergies, your doctor can help you determine if the benefits of the vaccine outweigh the risks.

Can non-U.S. citizens receive the vaccine and will receiving the vaccine affect my immigration status?

The COVID-19 vaccine is free and available to everyone regardless of citizenship or immigration status.

Receiving the vaccine will not negatively affect your immigration status or be used in “public charge” determinations. Data gathered during the vaccination is kept confidential and will not be used for immigration enforcement. The Department of Homeland Security said in a statement that it will not be present at vaccination sites for immigration enforcement.

If I had COVID-19 and recovered, should I get the vaccine?

Yes. Early findings suggest natural immunity from COVID-19 may not last long. More studies are needed.  We generally recommend getting vaccinated three months after recovering from COVID-19 infection. Your natural immunity should protect you during this and it may allow non-immune people to get the vaccine sooner. There is no harm in getting vaccinated before 90 days as long as you are beyond your isolation period.

Vaccine Location Questions

Am I required to present identification to be vaccinated?

For safety and accuracy reasons, Duke Health asks that you please bring a utility bill, statement, driver’s license, or other document which includes your name and current address. However, Duke Health will not withhold vaccinations or appointments for vaccinations if you cannot supply a form of identification. No patient without ID will be turned away.

How much of my personal data will be collected and will it be shared?

Duke Health collects name, address, date of birth, location at which the vaccine was given, when the vaccine was given, the person who administered the vaccine, information about the specific vaccine vial, and how the vaccine was given (ex. in the right arm muscle). This information is required by the state and by Duke Health in order to contact the patient after the visit to schedule additional visits. Information about race and ethnicity is also collected, which helps support North Carolina’s efforts for the equitable distribution of the COVID-19 vaccine. 

North Carolina is required to submit vaccination data to the CDC to meet federal requirements. Data submitted to the CDC will not be used to market commercial services to individual patients or nonpatients, assist in bill collecting services, or civil or criminal prosecution or enforcement, including but not limited to immigration enforcement.

Will there be interpreting services at my vaccine appointment?

Yes, there are interpreting services at all of our vaccine sites.

How many doses will I need?

The Pfizer and Moderna vaccines require two doses. Pfizer’s vaccine requires two doses of the vaccine 21 days apart. Moderna's second dose is administered one month after the first. The Johnson& Johnson vaccine requires one dose.

Other Vaccine Questions

How much does the vaccine cost?

The COVID-19 vaccine is available at no cost to you regardless of if you have health insurance. If you do have insurance, your insurance will be billed for an administration fee only, but you will not be charged. No patient without insurance will be turned away.

What are the differences between the Moderna, Pfizer and Johnson & Johnson vaccines?

Clinical trial data show the FDA-approved Moderna and Pfizer COVID-19 vaccines are equally effective after vaccination -- 95% for Pfizer and 94.1% for Moderna -- and are safe for most adults and across different ethnic and racial groups. The vaccines were studied extensively and tested successfully in 30,000 people before receiving FDA approval. Since approval, they have been safely administered to tens of millions of people.

The Johnson & Johnson vaccine is 67% effective at preventing moderate to severe disease from COVID-19 and 85% effective at preventing severe disease. The clinical trial also found the vaccine to be 100% effective at preventing hospitalization and deaths.

Pfizer and Moderna Vaccines Use mRNA Technology
Neither vaccine uses a live virus to help the body develop immunity, as some traditional vaccines do. Instead, both vaccines are messenger RNA vaccines (mRNA). This new vaccine technology teaches the body how to make a harmless piece of protein, called a spike protein, that triggers an immune response that protects you from COVID-19. Although this is a newer type of vaccine, researchers have been studying and working with mRNA vaccines for decades. Both COVID-19 vaccines were thoroughly tested before approval. The mRNA vaccines do not manipulate your DNA as they never enter the cell. More information is available on the CDC website.

The Janssen vaccine (Johnson & Johnson) does not use mRNA technology. Instead, it uses a harmless inactivated cold virus to help the body build an immune response against the coronavirus that causes COVID-19.

Differences between the Vaccines

  • Population Approved for Use 
    The Moderna vaccine and the Johnson & Johnson vaccine are approved for use in people 18 and older. The Pfizer vaccine is approved for use in people age 12 and older.
  • Dosage Timing
    Both vaccines require two doses, however, the timing for the second dose differs. The second Moderna dose is given 28 days after the initial dose; the second Pfizer dose is given 21 days after the initial dose. The Johnson & Johnson vaccine requires one dose.
  • Side Effects
    The vaccines may cause similar side effects including redness, swelling, and pain at the injection site, fever, fatigue, headache, chills, vomiting, diarrhea, muscle pain, and/or joint pain. These are signs that your immune system is building protection against the virus. There have been rare cases of a severe allergic reaction after the Pfizer vaccine, but not after the Moderna vaccine. This was not seen in the clinical trials.
  • Vaccine Storage
    Both vaccines require cold storage, however, not to the same degree. Moderna’s can be stored in a refrigerator freezer while Pfizer’s requires ultracold freezers. This makes the Moderna vaccine easier to distribute. The Johnson & Johnson vaccine does not require cold storage.

If I get the vaccine, do I still need to wear a mask and practice social distancing?

If you are fully vaccinated, you can safely resume most activities without wearing a mask or practicing social distancing. If you are not yet fully vaccinated or have not yet received your vaccine, keep wearing a mask, practicing social distancing, and frequently washing your hands until you are fully vaccinated to help reduce your chance of being exposed to and spreading the virus. In accordance with the new CDC guidance, masking, social distancing, and other safety measures are still required in certain settings such as health care settings (including all Duke Health hospitals and clinics), at childcare, schools, and camps, on public transportation, and in certain congregate settings like correctional facilities and homeless shelters.

Can I get my second vaccine dose at Duke if I got my first vaccine dose elsewhere?

Yes. If you need a second dose of the Pfizer or Moderna vaccine but did not receive your first dose at Duke, you can receive it at one of our walk-in clinics or you can schedule an appointment.

Johnson & Johnson Vaccine Questions

Is Duke Health offering the Johnson & Johnson COVID-19 vaccine?

Duke Health is offering the Johnson & Johnson vaccine after a thorough safety review by the CDC and FDA determined the use of the vaccine should resume. The CDC and FDA found the vaccine to be safe and effective in preventing COVID-19. The available data show that the vaccine’s known and potential benefits outweigh its known and potential risks in individuals 18 years of age and older. These data suggest that the chance of concerning side effects occurring after receiving the Johnson & Johnson vaccine is very low, but the FDA and CDC will remain vigilant in continuing to monitor people who receive any COVID-19 vaccine for unexpected events.

What are the side effects that the CDC and FDA to pause the use of the J&J vaccine?

A very small number of Johnson & Johnson vaccine recipients experienced severe and rare blood clots. The adverse reaction occurred among women between the ages of 18 and 59, and symptoms appeared six to 15 days after vaccination. The side effects associated with the small number of Johnson & Johnson vaccine recipients have not been found in people who received a Pfizer or Moderna vaccine

How common are the most concerning potential side effects?

The blood clot side effect is extremely rare. The CDC reports blood clots are occurring at a rate of about seven per one million vaccinated women between 18 and 49 years old. None of these cases have occurred at Duke or in North Carolina.

What side effects should I be aware of if I have already received the Johnson & Johnson vaccine?

People who’ve received the Johnson & Johnson vaccine and develop severe headache, abdominal pain, leg pain, or shortness of breath within six days to three weeks of vaccination should seek medical care.  These adverse reactions are extremely rare, but safety is our priority.

Are there other side effects that are not serious?

People who have received the Johnson & Johnson COVID-19 vaccine do not need to be concerned about common reactions to vaccines that occur within a few days of being vaccinated, including soreness, fatigue, low grade fever, or nausea. These are not associated with the more severe concern with blood clots.

Is the Johnson & Johnson vaccine considered safe for everyone to receive?

Available data show that the J&J vaccine’s known and potential benefits outweigh its known and potential risks in individuals 18 years of age and older, but the recent pause on J&J vaccine distribution has raised modest concerns about the rare side effects of blood clotting that have been reported in a few healthy young women who received the vaccine.

We acknowledge that some individuals will still be concerned about the very low risk of this severe side effect and may preferentially choose to receive one of the two-dose mRNA vaccines (Pfizer or Moderna) instead of the one-dose Johnson & Johnson vaccine. We have an ample supply of the Moderna and Pfizer vaccines. We recommend that people consult their personal physicians with specific questions about which vaccine may be best for them.