COVID-19 Vaccine FAQ

Below are frequently asked questions about the COVID-19 vaccines. For the most recent updates about the vaccine, including information about distribution phases, visit our COVID-19 Vaccine Information and Update page.

More Information for Michigan Medicine Employees

If you are a Michigan Medicine employee, or a University of Michigan student, staff or faculty member, visit the FAQs About COVID-19 Vaccines page on Michigan Medicine Headlines for more information about vaccine logistics and how to make a vaccination appointment.

About the COVID-19 Vaccines

What vaccines are available for COVID-19?

Three vaccines are available in the U.S. for COVID-19:

Full FDA Approval (with Emergency Use Authorization for 12-15 year-olds)

  • Pfizer Inc./BioNTech (trade name Comirnaty) received full approval from the U.S. Food and Drug Administration (FDA) August 23, 2021. The Pfizer vaccine is approved as a two-dose series for prevention of COVID-19 in individuals 16 years of age and older. It is also authorized under Emergency Use Authorization (EUA) to be administered to:
    • Prevent COVID-19 in individuals 12 through 15 years, and
    • Provide a third dose to individuals 12 and older who have been determined to have certain kinds of immunocompromise

Emergency Use Authorization

  • Moderna received Emergency Use Authorization (EUA) in December 2020
  • Johnson & Johnson received EUA approval for their Janssen vaccine in late February 2021. Following a thorough safety review, the CDC and FDA recommended the pause that began on April 13 should be lifted and use of the vaccine should resume. Michigan Medicine has not administered any of the Johnson & Johnson/Janssen vaccine through our patient vaccine program. Some individuals received the J&J vaccine during their participation in a Michigan Medicine research trial. If you received the J&J vaccine as part of a research trial, contact your study administrator with questions.

More information can be found here: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations-process.html.

How do the vaccines work?

Each vaccine uses a slightly different approach with the same goal: to induce an immune response in the body against SARS-CoV2, the virus that causes COVID-19. The vaccines produced by Pfizer and Moderna are both mRNA vaccines. The Janssen vaccine (from Johnson & Johnson) is a viral vector vaccine.

The Pfizer and Moderna mRNA vaccines contain a message from the COVID-19 virus that that gives our cells instructions for how to make a harmless protein that is unique to the virus.

After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies also recognize that the protein should not be there and build immune cells that will remember how to fight the virus that causes COVID-19 if we are exposed in the future. Both vaccines require two shots, with the second shot received 21 to 28 days after the first, depending on the vaccine. Watch a video about how mRNA vaccines work.

The Johnson & Johnson/Janssen vaccine creates a similar immune system response but uses an inactivated harmless cold virus (adenovirus 26) to deliver instructions to your immune system for fighting the virus that causes COVID-19. It requires only one shot.

Following a thorough safety review, the CDC and FDA have determined that the recommended pause that began on April 13 regarding the use of the Johnson & Johnson (Janssen) COVID-19 vaccine in the U.S. should be lifted and use of the vaccine should resume. Michigan Medicine has not administered any of the Johnson & Johnson/Janssen vaccine through our patient vaccine program. Some individuals received the J&J vaccine during their participation in a Michigan Medicine research trial. If you received the J&J vaccine as part of a research trial, contact your study administrator with questions.

How many shots am I going to need?

The Pfizer vaccine requires two doses, 21 days apart. The Moderna vaccine requires two doses, 28 days apart. It takes time for your body to build protection after any vaccination. The two COVID-19 vaccines may not protect you until one to two weeks after your second shot.

The CDC recommends that people with compromised immunity who have received two doses of the Pfizer or Moderna vaccine receive a third dose, which can be given at least 28 days after your second dose.

The J&J vaccine requires only one shot. Additional dose vaccines are not recommended for people who received the Johnson & Johnson/Janssen vaccine at this time.

What ingredients are in the Pfizer vaccine?

The Pfizer vaccine contains:

  • Messenger ribonucleic acid (mRNA) – the main, active ingredient that elicits an immune response and the production of antibodies
  • Lipids (including ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate), 2 [(polyethylene glycol)-2000]-N,N-ditetradecylacetamide, 1,2-Distearoyl-sn-glycero-3- phosphocholine, and cholesterol) – an outside coating or shell of fat that protects the mRNA from destruction as it is being stored, administered and delivered to cells
  • Potassium chloride; monobasic potassium phosphate; sodium chloride (salt); dibasic sodium phosphate dehydrate – salts that are used to maintain proper levels of acidity (pH)
  • Sucrose – a sugar that stabilizes the suspension

What ingredients are in the Moderna vaccine?

The Moderna COVID-19 vaccine contains:

  • Messenger ribonucleic acid (mRNA) - the main, active ingredient that elicits an immune response and the production of antibodies
  • Lipids (SM-102, polyethylene glycol [PEG] 2000 dimyristoyl glycerol [DMG],cholesterol, and 1,2-distearoyl-sn-glycero-3-phosphocholine [DSPC])- an outside coating or shell of fat that protects the mRNA from destruction as it is being stored, administered and delivered to cells
  • Tromethamine,tromethamine hydrochloride, acetic acid, sodium acetate - used to maintain proper pH
  • Sucrose – a sugar that stabilizes the suspension

What ingredients are in the Janssen vaccine?

The Johnson & Johnson COVID-19 vaccine contains:

  • Recombinant, replication-incompetent adenovirus type 26 expressing the SARS-CoV-2 spike protein: the active ingredient that enters human cells and elicits the immune response without replication.
  • Citric acid monohydrate: an antioxidant that helps maintain stability of the active ingredient
  • Trisodium citrate dihydrate: used to help control pH (acidity)
  • Ethanol: used to keep the other ingredients dissolved and in solution form
  • 2-hydroxypropyl-?-cyclodextrin (HBCD): used to improve the solubility and stability of the active ingredient
  • Polysorbate-80: this is a common food additive used in several vaccines as an emulsifier (to hold other ingredients together). Compared with its use in foods, there is very little polysorbate-80 in vaccines.
  • Sodium chloride: a salt used to control acidity and tonicity of the solution

Following a thorough safety review, the CDC and FDA have determined that the recommended pause that began on April 13 regarding the use of the Johnson & Johnson (Janssen) COVID-19 vaccine in the U.S. should be lifted and use of the vaccine should resume. Michigan Medicine has not administered any of the Johnson & Johnson/Janssen vaccine through our patient vaccine program. Some individuals received the J&J vaccine during their participation in a Michigan Medicine research trial. If you received the J&J vaccine as part of a research trial, contact your study administrator with questions.

How are the three vaccine options different from one another?

The key difference between the Janssen (Johnson & Johnson) vaccine and the Pfizer/BioNTech and Moderna vaccines is that the Janssen vaccine requires only one dose. Both the Pfizer/BioNTech and Moderna vaccine require two doses.

Additionally, the Janssen vaccine uses an inactivated adenovirus (adenovirus 26; similar to the virus that causes the common cold) instead of the mRNA technology used in the Moderna and Pfizer/BioNTech vaccines. While Moderna and Pfizer both use the same technology, they contain slightly different mRNAs and different ingredients used to protect the mRNA, maintain the pH and stabilize the solution.

All three vaccines effectively prevent serious illness and death from COVID-19 and have similar potential side effects.

How effective is the vaccine?

In clinical trials, the Pfizer and Moderna vaccines were shown to be about 95% effective at preventing illness caused by the coronavirus. The one-shot Johnson & Johnson vaccine has been shown to be 66% effective, according to the CDC.

How much does the COVID-19 vaccine cost?

There is no out-of-pocket cost to receive the COVID-19 vaccine.

The federal government is providing the vaccine itself at no cost to patients.

There is a vaccine administration fee for supplies, facilities, staffing and other expenses that will be covered in full by your insurance company, Medicaid, Medicare, or the federal government if you do not have insurance.

If you receive a bill in error, please call Patient Financial Experience at 855-855-0863 or 734-615-0863.

Where can I learn more about the COVID-19 vaccines?

For current and accurate information  about the COVID-19 vaccines visit:

Third Dose Vaccine Availability

Who should get a third dose of the COVID-19 vaccine?

The CDC recommends that anyone who has moderately to severely compromised immunity and received both doses of the Pfizer or Moderna vaccine get a third dose of the COVID-19 vaccine. This includes people who have:

  • Been receiving active cancer treatment for tumors or cancers of the blood
  • Received an organ transplant and are taking medicine to suppress the immune system
  • Received a stem cell transplant within the last two years or are taking medicine to suppress the immune system
  • Moderate or severe primary immunodeficiency (such as DiGeorge syndrome, Wiskott-Aldrich syndrome)
  • Advanced or untreated HIV infection
  • Active treatment with high-dose corticosteroids or other drugs that may suppress your immune response

Patients will be asked to confirm that they have compromised immunity when scheduling a third dose appointment. No additional documentation will be required, but you will be asked to bring documentation of your first and second doses with you to your appointment.

Additional dose vaccines are not recommended for people who received the Johnson & Johnson/Janssen vaccine at this time.

The FDA and CDC continue to evaluate data regarding the need for additional doses for other populations.

Can you get a different type of vaccine for your third dose than your previous COVID-19 vaccine doses?

The CDC recommends you receive the same mRNA vaccine for your third dose, if possible. However, if the type of mRNA vaccine you received previously is not available, either mRNA vaccine can be administered for your third dose.

When should you get a third dose of the COVID-19 vaccine?

Patients with compromised immunity can receive their third dose at least 28 days after receiving your second dose.

What documentation will be required to get a third vaccine dose?

Patients will be asked to confirm that they have compromised immunity when scheduling their third dose appointment. No additional documentation will be required, but you will be asked to bring documentation of your first and second doses with you to your appointment.

How can I schedule a third dose vaccine appointment at Michigan Medicine?

Patients with compromised immunity who have received both doses of an mRNA vaccine at least 28 days ago can schedule their third dose appointment online through the MyUofMHealth patient portal. If you do not have a portal account you can schedule an appointment by calling the COVID-19 Vaccine Scheduling Call Center at 734-763-6336 (select option 1, then option 2 to speak with an agent) seven days a week from 8 a.m. to 6 p.m.

Vaccines are also widely available at local pharmacies. See our Finding Vaccines page for tips on how to find a vaccine appointment in your area.

Scheduling an Appointment and Getting the Vaccine

Who is able to get the vaccine?

All individuals age 12 and older are now eligible to receive a COVID-19 vaccine. For information about the COVID-19 vaccine and adolescents and children ages 12-15, visit our COVID-19 Vaccines for Adolescent and Children page on MottChildren.org

How can a Michigan Medicine patient schedule an appointment to receive the COVID-19 vaccine?

To ensure vaccines are being administered as quickly and fairly as possible, vaccine invitations are managed exclusively through our COVID-19 vaccine team. Please do not call or message your provider about scheduling a vaccine appointment. 

Registered MyUofMHealth patient portal users can schedule a vaccine appointment directly through the portal.

If you do not have a MyUofMHealth portal account, you may sign up for one on MyUofMHealth.org.

Individuals who are not portal users can schedule a vaccine by calling 734-763-6336.

It is possible that you might see no available appointments when you log into the MyUofMHealth patient portal. Please keep checking back, as new slots will open up each week.

Can I get my vaccination somewhere else?

The State of Michigan’s vaccination distribution strategy is to offer broad access to vaccination through health departments and pharmacies in addition to hospitals and clinics. We strongly encourage our patients to get vaccinated wherever it is convenient for you to do so.

If you received your first dose of a vaccine somewhere else, and would like to get your second dose at Michigan Medicine, you may do so as long as proof of initial vaccines can be provided. Call the COVID-19 Vaccine Scheduling Call Center at 734-763-6336 (select option 1, then option 2) 7 days a week from 8 a.m. to 6 p.m. for more information about scheduling your second vaccine dose at Michigan Medicine.

Visit our Finding Vaccines in Your Area page for more tips and resources for getting vaccinated.

If you receive a vaccine from another provider in the State of Michigan (excluding the VA), your vaccination record will be entered into a statewide database (MCIR) that securely connects with our electronic medical record system.

If you receive your vaccination from a provider outside of Michigan, or from the VA, please see the section "If You Have Been Vaccinated Elsewhere" section at the bottom of the Finding Vaccines in Your Area page for instructions on how to notify your Michigan Medicine provider that you have been vaccinated.

Can I choose which vaccine I'd like to receive?

Michigan Medicine receives vaccine supply from different manufacturers as allocated by the State of Michigan. We open up new appointments each week based on the available vaccine supply. While you won’t be able to request a specific vaccine, you may schedule your appointment at a clinic where your preferred vaccine is being administered. To learn which vaccines will be administered at a specific vaccine clinic, see the Vaccine Distribution Update at the top of our Vaccine Information and Update page. Please note that locations where specific vaccines are administered may change based on vaccine supply and current operations.

I got my COVID-19 vaccination from another clinic/location outside of Michigan Medicine. Do I need to let Michigan Medicine know?

If you were vaccinated in the State of Michigan, your vaccination should be automatically documented in the state’s immunization registry, and your Michigan Medicine provider will be able to access this information to pull it into your medical record at your next appointment.

If you receive your vaccination from a provider outside of Michigan, or from the VA, please see the section "If You Have Been Vaccinated Elsewhere" section at the bottom of the Finding Vaccines in Your Area page for instructions on how to notify your Michigan Medicine provider that you have been vaccinated.

I've scheduled my vaccination appointment. How do I find where to go, and what should I expect?

Visit the Your Vaccination Appointment page for a video about what to expect and maps and other information about clinic locations.

Vaccine Restrictions and Special Cases

Can I get the vaccine if I’ve had COVID-19 or think I may have had COVID-19 in the past?

According to CDC, vaccination should be offered regardless of history of prior symptomatic or asymptomatic SARS-CoV-2 infection. Data from phase 2/3 clinical trials suggest vaccination is safe and likely efficacious in these people.

Current evidence suggests that people who have had COVID-19 may be protected for up to 90 days after their initial infection, so they may decide to wait until after this period, if desired.

Can I get the vaccine if I've participated in a COVID-19 clinical research trial?

Go to your study team coordinator with any questions you have about your eligibility to receive the COVID-19 vaccine.

Are there any restrictions about who can receive the COVID-19 vaccine?

Yes, you cannot receive the vaccine if:

  • You have been diagnosed with COVID-19 in the last 10 days 
  • You have received an infusion of COVID-19 monoclonal antibodies in the past 90 days

Can the COVID-19 vaccine be administered with other vaccines?

The CDC has updated guidance around receiving the COVID-19 vaccine with other non-COVID-19 vaccines. Previously, the guidance was to have a minimum 14-day interval between the COVID-19 vaccine and any other vaccine. The new guidance now states that the COVID-19 vaccine and other vaccines may now be administered without regard to timing. This includes simultaneous administration of COVID-19 vaccine and other vaccines on the same day, as well as co-administration within 14 days.

I already had COVID-19 and recovered. Do I still need to get vaccinated?

Yes, you should be vaccinated regardless of whether you already had COVID-19 because:

  • Research has not yet shown how long you are protected from getting COVID-19 again after you recover from COVID-19.
  • Vaccination helps protect you even if you’ve already had COVID-19.

Evidence is emerging that people get better protection by being fully vaccinated compared with having had COVID-19. One study showed that unvaccinated people who already had COVID-19 are more than 2 times as likely than fully vaccinated people to get COVID-19 again. If you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.

If I have allergies and am worried about an allergic reaction, should I go to a specific vaccine clinic?

Every Michigan Medicine vaccine clinic location is equipped to administer COVID-19 vaccines safely. When scheduling your vaccine appointment in your MyUofMHealth portal account, you will be asked a question about allergic or anaphylactic reactions. Similarly, you will be asked this question again at the time of vaccination. Please answer the question in order to schedule your vaccine appointment.

If you have a history of allergies, you will be observed for a longer period of time after your injection (at least 30 minutes) by medical personnel onsite and should report any symptoms to the charge nurse during your observation period. Medical staff at all locations are equipped with anaphylaxis kits and supplies to quickly treat anyone experiencing an allergic reaction to the vaccine. 

Safety, Side Effects and Other Concerns

How did a vaccine get developed and approved so quickly? Was the process rushed?

Producing a vaccine against COVID-19 has been the top priority of scientists and governments around the world to help bring an end to the pandemic. With the coordinated and enormous investment of resources, development of these vaccines has been accelerated, all while maintaining standards for safety and efficacy.

Rather than eliminating steps from traditional vaccine development timelines, steps are proceeding simultaneously, such as scaling up manufacturing while safety and efficacy data are collected.

How do we know if the vaccines are safe?

COVID-19 vaccines were tested in large clinical trials that included tens of thousands of people. This is done to make sure they meet safety standards and see how the vaccines offer protection to people of different ages, races, and ethnicities, as well as those with different medical conditions. No significant safety concerns were identified in the clinical trials. At least 8 weeks of safety data were gathered in the trials. It is unusual for side effects to appear more than 8 weeks after vaccination.

Important note: The development of these vaccines has been accelerated while maintaining all safety standards. Rather than eliminating steps from traditional vaccine development timelines, steps were happening at the same time, such as scaling up manufacturing while safety and efficacy data are collected.

Is the vaccine safe for those who are pregnant, breastfeeding, or trying to conceive?

We have reviewed the available data on the three COVID-19 vaccines available in the United States, as well as society and governmental organization opinions about the use of the vaccine in women who are pregnant, who are breastfeeding, and who may become pregnant. We will continue to review information as it becomes available.

During Pregnancy: We believe that those who are pregnant should have access to COVID-19 vaccination. While the known absolute risk is low, those who get infected with COVID-19 while pregnant have an increased risk of severe illness, ICU admission, needing to go on a ventilator, and even death. The science suggests that the benefits to receiving the COVID-19 vaccine are great.

Available data suggest that the vaccine is effective when received during pregnancy. There is evidence that when a person is vaccinated during pregnancy, their newborn may have some protection from becoming infected with COVID-19. Available data on those who were vaccinated during pregnancy suggest it is safe.

Breastfeeding: COVID-19 vaccination is recommended for those who are breastfeeding.

Trying to Conceive: There is no evidence that COVID-19 vaccines cause infertility. Vaccination is recommended for those who intend to become pregnant.

To help make your decision about receiving the vaccine, be sure to speak with your health care provider.

Is the vaccine safe for people with conditions or medications that can weaken the immune system?

The early clinical trials did not test the vaccines in these populations but based on the current data, the benefit of receiving the COVID-19 vaccine is greater than the risks of getting COVID-19. Talk to your health care provider about the potential risks and benefits of the vaccine in your specific situation. 

What are the side effects of the vaccine?

In the vaccine clinical trials, most people did not have serious problems after being vaccinated, and symptoms usually went away on their own within a week. More people experienced these side effects after getting the second dose than the first one.

Common side effects that have been reported with available COVID-19 vaccines include:

  • injection site pain, swelling, or redness
  • tiredness
  • headache
  • muscle pain
  • chills
  • joint pain
  • fever
  • nausea
  • feeling unwell
  • swollen lymph nodes (lymphadenopathy)

Side effects of individual COVID-19 vaccines may vary. You can find more information about what to expect after getting vaccinated on the CDC website: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/expect/after.html

If you get the vaccine and become immune, then are exposed to it, can you pass the virus on to others from your exposure?

Based on our experience with other vaccines and early data from the COVID-19 vaccines, it is likely that people who are vaccinated will have enough immunity where they will not pass the virus to others if exposed, but this is not 100 percent certain.

I’m not sure about the COVID-19 vaccine. Where can I find information to help me decide?

Maybe you’ve heard a claim about the COVID vaccines on social media or from a friend or relative that is making you wary about getting vaccinated when it’s your turn.  

We collected some of the most widespread rumors, claims, myths and worries about the COVID-19 vaccines, and checked them out with help from Michigan Medicine experts. Read the questions and answers on our Michigan Health blog post: “Not Sure About the COVID-19 Vaccine? Get the Facts, Then Decide”.

After Vaccination

How long do the vaccines protect against infection?

Health care professionals and researchers are still learning about COVID-19 and new information is discovered nearly every day that is helpful in the fight against this disease. Because COVID-19 is still a relatively new virus, it is difficult to know exactly how the virus affects the body long-term and how long immunity from natural infection lasts.

Therefore, it is also difficult to predict how long a vaccine will provide protection against the virus. As the vaccines are administered and new information is gathered, additional data about how long it will protect against the virus will be made available. 

Will the vaccine be given annually or is it only for this year?

This is not known at this time. Scientists are continuing to collect data about long-term immunity to SARS-CoV2.

Should I get a "booster" or third dose of the vaccine?

The CDC recommends that people who have compromised immunity and received both doses of an mRNA vaccine should receive a third dose of the mRNA vaccine. See the “Third Dose Vaccine Availability” section on this page for more information.

Additional dose vaccines are not recommended for people who received the Johnson & Johnson/Janssen vaccine at this time.

The FDA and CDC continue to evaluate data regarding the need for additional doses for other populations. At this time, no other individuals are eligible to receive a third dose of the COVID-19 vaccine.

Do I need to wear a mask and avoid close contact with others if I have received 2 doses of the vaccine?

As more of the U.S. population has gotten vaccinated, state and local mask requirements have been loosened based on CDC recommendations. However, CDC guidance issued in late July 2021 encourages indoor masking in public places in areas of substantial or high transmission. See the CDC COVID Data Tracker for an interactive tool showing up-to-date information about the status of COVID transmission throughout the U.S.

Please note that masks or face coverings are still required for all staff, patients and visitors while inside Michigan Medicine facilities and the courtyard of the main medical campus, regardless of vaccination status.