Latest Questions about COVID-19 Vaccines

Q: What does FDA’s approval of the biologics licensure application (BLA) for Comirnaty, the Pfizer-BioNTech COVID-19 Vaccine, mean for my clinic?

A: On August 23, 2021, FDA approved the BLA for Pfizer-BioNTech COVID-19 Vaccine for individuals age 16 years and older; its trade name is Comirnaty. The vaccine remains authorized for emergency use for children age 12 through 15 years and for administration of an additional dose in immunocompromised people. For simplicity, the Ask the Experts COVID-19 section will continue, for now, to refer to Comirnaty as Pfizer-BioNTech COVID-19 Vaccine. No changes have been made to the storage, handling, or vaccine ordering requirements as a result of licensure. Clinicians should continue to administer this vaccine in accordance with current ACIP recommendations and CDC guidelines.
 
The FDA issued an updated Fact Sheet that reflects the new trade name and combines information for individuals receiving the vaccine in accordance with its licensed indication with information for those receiving the product under the terms of its emergency use authorization (EUA).
 
All clinics providing the Pfizer-BioNTech COVID-19 Vaccine should use the updated Fact Sheet for all recipients and caregivers: www.fda.gov/media/144414/download.
 
The Fact Sheet for healthcare providers is here: www.fda.gov/media/144413/download.
 
The link to the prescribing information (PI) for Comirnaty is here: www.fda.gov/media/151707/download.

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Q. Are COVID-19 vaccines recommended during pregnancy?

A: Yes. COVID-19 vaccination is recommended for all people age 12 years and older, including people who are pregnant, lactating, trying to get pregnant now, or planning for future pregnancy. Pregnant people are at increased risk of severe complications and death from COVID-19 compared to non-pregnant people of the same age. They can be administered any authorized vaccine: ACIP does not state a product preference. However, women younger than age 50 years should be aware of the rare risk of blood clots with low platelet counts (thrombosis with thrombocytopenia syndrome [TTS]) after receipt of the Janssen vaccine and the availability of other FDA-authorized or licensed COVID-19 vaccines (mRNA vaccines) that do not have that risk.
 
CDC, the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM) all recommend vaccination of pregnant people at any stage of pregnancy.
 
For more details about COVID-19 vaccination during pregnancy, visit CDC’s webpage, “COVID-19 Vaccines while Pregnant or Breastfeeding”: www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/pregnancy.html.

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Q. Are COVID-19 vaccines recommended if the recipient is breastfeeding?

A: Yes. COVID-19 vaccination is recommended for all people age 12 years and older, including people who are lactating. Lactating women younger than age 50 should be aware of the increased risk for TTS with the Janssen vaccine and the availability of other FDA- authorized or licensed COVID-19 vaccines (i.e., mRNA vaccines).
 
There are limited data on the safety of currently available COVID-19 vaccines on the breastfed infant or milk production/excretion. However, the currently available COVID-19 mRNA and non-replicating viral vector vaccines cannot cause infection in either the lactating person or the infant. More data are needed to determine if COVID-19 antibodies present in breastmilk convey protection against SARS-CoV-2 infection for infants.

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Q. Are COVID-19 vaccines safe during pregnancy?

A: A growing body of evidence on COVID-19 vaccination during pregnancy has not indicated any safety or effectiveness concerns for vaccination at any stage of pregnancy; the benefits of vaccination outweigh any known or potential risks of COVID-19 vaccination during pregnancy. The currently authorized or licensed COVID-19 vaccines are non-replicating vaccines and cannot cause infection in either the mother or the fetus. No evidence exists of risk to the fetus from vaccinating pregnant people with non-replicating vaccines in general.
 
No safety concerns were found in animal developmental and reproductive toxicity studies of animals that received Pfizer-BioNTech, Moderna, or Janssen vaccines. Reassuring early safety data on mRNA COVID-19 vaccines administered to people during pregnancy have been published by CDC. Data from the Vaccine Adverse Events Reporting System (VAERS), the v-safe surveillance system, and the v- safe pregnancy registry have not signaled any safety concerns for pregnant people who were vaccinated or their infants. The vaccine manufacturers are following the pregnancy outcomes of people in the clinical trials who became pregnant. Additional studies in pregnant people are continuing to fully evaluate pregnancy and birth outcomes.
 
Pregnant individuals should be vaccinated and are encouraged to enroll in CDC’s voluntary COVID-19 vaccine safety surveillance system, v-safe. The v-safe pregnancy registry follows outcomes among pregnant people who are vaccinated.

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Q. Can COVID-19 vaccination lead to fertility problems?

A: There is currently no evidence that any of the COVID-19 vaccines affect current or future fertility. In fact, there is currently no evidence that any vaccines cause fertility problems. Many individuals have become pregnant after receiving COVID-19 vaccine; ongoing long-term studies of pregnancy outcomes following vaccination are underway.

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Q. What is the difference between an “additional dose” of COVID-19 vaccine recommended for an immunocompromised person and a “booster dose”?

A:  An additional dose of mRNA vaccine after an initial primary series of mRNA vaccine is recommended by CDC for people with moderate or severe immunocompromise. In these populations, the immune response following the primary 2-dose series is likely to be insufficient, and the additional dose increases the likelihood of developing a sufficient immune response. The additional dose of mRNA vaccine should not be delayed. It may be given 28 days or more after the last dose of the primary series.
 
The term “booster dose” applies to an additional dose of vaccine administered only after the initial sufficient immune response to the primary series is likely to have waned over time. The interval between a primary series and a booster dose is at least several months.
 
For details about vaccination of immunocompromised people, see the section on special populations or CDC’s interim clinical considerations for the use of COVID-19 vaccines: www.cdc.gov/vaccines/covid-19/clinical- considerations/covid-19-vaccines-us.html#considerations-additional-vaccine-dose.

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Q. Why is an additional dose of mRNA vaccine recommended for some immunocompromised people?

A: Immunocompromised people are at increased risk for severe COVID-19 illness. Studies have shown a reduced immune response to COVID-19 vaccines in some people with immunocompromising conditions or people who take immunosuppressive medications. Small studies have shown that an additional mRNA vaccine dose in some immunocompromised people who had already completed the primary mRNA vaccine series increased the proportion of people who showed an antibody response to vaccination, which may mean they are better protected from illness. Side effects were similar to the side effects of prior doses.
 
Although the benefit of the additional dose of mRNA vaccine for a moderately or severely immunocompromised person is not precisely known, the available evidence of potential benefit and acceptable safety supports its use.
 
Immunocompromised people who receive an additional dose should be counseled that they may still have a reduced immune response to COVID-19 vaccination, even after an additional dose. They should be advised to continue other recommended infection prevention measures, such as wearing a face mask and avoiding crowds, to limit their risk of exposure to the SARS-CoV-2 virus.

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Q. Exactly which immunocompromised groups are recommended to receive an additional dose of mRNA vaccine?

A: The age groups eligible are those already eligible for mRNA vaccines: people age 12 years or older (Pfizer-BioNTech) and people age 18 years or older (Moderna).
 
The conditions and treatments that may result in moderate or severe immunocompromise in these eligible age groups include but are not limited to:

• Active treatment for solid tumor and hematologic malignancies
• Receipt of solid-organ transplant and taking immunosuppressive therapy
• Receipt of CAR-T-cell or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
• Moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome)
• Advanced or untreated HIV infection
• Active treatment with high-dose corticosteroids (in other words, 20 mg or more of prednisone or equivalent per day), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, tumor-necrosis factor (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory.

Additional factors to consider in assessing the general level of immune competence in a patient include disease severity, duration, clinical stability, complications, comorbidities, and any potentially immune-suppressing treatment. A patient’s clinical care team is in the best position to evaluate the degree of immunocompromise and timing of vaccination.
 
For additional information, please review CDC’s interim clinical considerations for COVID-19 vaccines: www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines- us.html#considerations-additional-vaccine-dose.

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Q. Should I conduct serologic testing or cellular immune testing before or after offering an additional dose of mRNA vaccine to an immunocompromised patient?

A: No. At this time, serologic testing or cellular immune testing before or after an additional dose (outside the context of research studies) is not recommended.

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Q. Does it matter which brand of mRNA vaccine I give to an immunocompromised person who is recommended to receive an additional dose?

A: CDC recommends that the additional dose should be the same brand as the primary series. However, if the same brand is unavailable, you may administer the other mRNA vaccine. An immunocompromised person should not receive more than 3 mRNA vaccine doses.

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Q. My patient takes high dose steroids and received a single dose of Janssen COVID-19 Vaccine (Johnson & Johnson) in late March 2021. He meets the definition of moderate or severe immunocompromise. Should I give him an additional dose of Janssen or mRNA vaccine?

A: At this time, there are insufficient data to recommend an additional dose either of mRNA vaccine or Janssen vaccine for immunocompromised patients who received primary COVID-19 vaccination with Janssen vaccine. Additional guidance from FDA and CDC is expected once data are available.

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Q. My patient has had a kidney transplant and wants to know if he is considered fully vaccinated for public health purposes (e.g., allowed to enter a restaurant where proof of immunization is required) if he has received the 2-dose mRNA primary series but has not yet had an additional dose?

A: Yes. CDC guidance states that, for the purposes of public health classification, all vaccinated individuals may be classified as fully vaccinated beginning two weeks after receipt of either a single dose of Janssen vaccine or a two-dose primary series of mRNA vaccine. A person known to be immunocompromised is not required to receive a third mRNA dose to be considered fully vaccinated. However, he should be counseled to continue to practice preventive measures, such as wearing a mask and avoiding crowds, even after an additional dose, to limit his risk of exposure to SARS-CoV- 2.

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Q. We have a patient who was fully vaccinated with a COVID-19 vaccine not authorized in the U.S. Do we need to revaccinate?

A: Not necessarily. People who completed a COVID-19 vaccination series with a vaccine that has been authorized for emergency use by the World Health Organization (WHO) do not need any additional doses with an FDA-authorized COVID-19 vaccine. People who completed or partially completed a COVID-19 vaccine series with a vaccine that is not authorized by either FDA or WHO may be offered an FDA-authorized COVID-19 vaccine series. The minimum interval between the last dose of a non-FDA authorized vaccine and an FDA-authorized COVID-19 vaccine is 28 days.
 
As of August 13, 2021, WHO has listed the following vaccines for emergency use:

• Pfizer-BioNTech COVID-19 vaccines (also known as Comirnaty, tozinameran)
• AstraZeneca-Oxford COVID-19 vaccines (also known as ChAdOx1-S, Covishield, Vaxzevria)
• Janssen (Johnson & Johnson) COVID-19 Vaccine
• Moderna COVID-19 Vaccine (also known as Spikevax)
• Sinopharm COVID-19 Vaccine (also known as BBIBP-CorV)
• Sinovac COVID-19 Vaccine (also known as CoronaVac)

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Q. Have any COVID-19 vaccines been associated with Guillain-Barré syndrome (GBS)?

A: Reports to the Vaccine Adverse Event Reporting System (VAERS) following use of Janssen COVID-19 Vaccine indicate an increased risk of GBS within 42 days of vaccination. Investigations to assess whether Janssen vaccine causes GBS are ongoing. Although the chance of GBS occurring is low, Janssen vaccine recipients should be counseled to seek medical attention promptly if symptoms of GBS occur, such as progressive muscle weakness. Currently, no association has been observed between GBS and mRNA COVID-19 vaccines.
 
Patients with a history of GBS may receive Janssen COVID-19 Vaccine, but should be counseled about the potential increased risk of GBS and the availability of alternative vaccine options for COVID-19 protection.

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Q. Tell me about mRNA COVID-19 vaccines and the risk of myocarditis and pericarditis.

A: Reports of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the tissue surrounding the heart) within a few days of mRNA COVID-19 vaccination have prompted the FDA to include information about these conditions in the Fact Sheets for each mRNA vaccine. There has not been a similar reporting pattern observed after receipt of Janssen COVID-19 Vaccine.
 
ACIP conducted a risk assessment and observed that the reported risk was rare, but was most commonly reported in males age 12 through 29; reported cases have occurred more often after dose 2 than dose 1. In most cases, patients who were diagnosed with myocarditis or pericarditis after mRNA vaccination have responded well to medication and rest and had prompt improvement of symptoms. ACIP has concluded that the benefit of vaccination clearly outweighs the risk of myocarditis or pericarditis.
 
People receiving mRNA vaccines, especially males age 12 through 29, should be counseled about the risk of myocarditis or pericarditis and advised to seek medical attention promptly if they develop chest pain, shortness of breath, or feelings of a fast, fluttering, or pounding heartbeat.
 
CDC has published additional clinical considerations for patients with myocarditis or pericarditis following mRNA vaccination: www.cdc.gov/vaccines/covid-19/clinical-considerations/myocarditis.html.

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Q. My patient had an episode of myocarditis 5 years ago. Is a history of myocarditis a contraindication or precaution to vaccination with an mRNA vaccine?

A: People who have a history of myocarditis or pericarditis unrelated to mRNA COVID-19 vaccination may receive any currently FDA-authorized or licensed COVID-19 vaccine after the episode of myocarditis or pericarditis has completely resolved. This includes resolution of symptoms attributed to myocarditis or pericarditis, as well as no evidence of ongoing heart inflammation or damage as determined by the person’s clinical team.
 
Individuals who experience myocarditis or pericarditis after their first mRNA vaccination are advised to defer receiving the second dose until additional safety data are available. If such a person elects to receive a second dose, they should wait until their episode of myocarditis or pericarditis has fully resolved and make the decision in consultation with their clinical team.
 
For additional details, see CDC’s interim clinical considerations for COVID-19 vaccination of people with certain underlying health conditions: www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html#underlying- conditions.

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