The COVID-19 vaccine is effective in preventing hospitalization and death from COVID-19. As a newer vaccine product, there are many questions that pediatricians and patients/families have. Below are answers to some of the most common questions.
Please note that this information will be updated regularly as data about COVID-19 vaccine becomes available.
COVID-19 Vaccine Recommendations
Which COVID-19 vaccines have been approved and/or authorized for use in the US?
The US has two mRNA and one protein subunit COVID-19 vaccines approved for use. The CDC has recommended COVID-19 vaccines with a preference for people to receive an mRNA vaccine (Pfizer-BioNTech and Moderna) or the protein subunit vaccine (Novavax).
All recommended mRNA vaccine products are now bivalent. The monovalent COVID-19 mRNA vaccines should no longer be administered.
Individuals who have received the monovalent Novavax vaccine series are recommended to receive a dose of bivalent mRNA COVID-19 vaccine. If they cannot or will not receive a bivalent mRNA vaccine, an additional dose of monovalent Novavax vaccine may be administered.
mRNA Vaccine ((Pfizer-BioNTech and Moderna)
- FDA EUA for bivalent COVID-19 Vaccine (Pfizer-BioNTech)
- FDA Fact Sheet for Healthcare Professionals (Pfizer-BioNTech)
- FDA EUA for bivalent COVID-19 vaccines (Moderna)
- FDA Fact Sheet for Healthcare Professionals (Moderna)
- FDA Healthcare Provider Letter (Moderna)
- CDC ACIP Recommendation for bivalent booster doses
- CDC Effectiveness of Bivalent mRNA Vaccines in Preventing Symptomatic SARS-CoV-2 Infection
Novavax Protein Subunit Vaccine
FDA EUA for individuals 12 years of age and older / Fact Sheet for Healthcare Providers Administering Vaccine
Which COVID-19 vaccine should I recommend to my patients?
AAP recommends using COVID-19 vaccines that are approved through an Emergency Use Authorization (EUA) or Biologics License Application (BLA), recommended by CDC, and appropriate for your patients’ age and health status. For mRNA vaccines, only bivalent products should be administered. Pediatricians should administer whichever formulation is available in their communities to achieve the highest vaccination coverage.
Children and adolescents 6 months of age and older who do not have contraindications should be vaccinated to protect them against COVID-19 as soon as possible. COVID-19 vaccines are life-saving. Delaying immunization leaves an individual vulnerable to infection for a longer period of time, placing them at greater risk of serious illness and death. AAP also supports coadministration of COVID-19 vaccines with other vaccines on the immunization schedule. See AAP policy.
Which Moderna or Pfizer-BioNTech vaccine dose should a child receive if they will have a birthday between doses?
In general, the vaccine product and size of the dose a child gets is based on how old they are on the day that they get the COVID shot. There are some exceptions, however.
A child turning from age 4 years to 5 years between Pfizer doses should receive all three doses with Pfizer maroon cap vials (for those ages 6 months – 4 years).
Children receiving Moderna vaccine who turn from age 5 years to 6 years during their 2-dose vaccine series, follow dosing recommendations based on age at the start of the vaccine series.
Can you “mix and match” vaccine products for one child?
The Pfizer-BioNTech COVID vaccine and the Moderna COVID vaccine are the two products that are authorized for children ages 6 months through 12 years old. In general, children should receive the same product for all doses recommended for their age in the vaccination series. One exception is that children who received a dose of Moderna COVID-19 vaccine at age 5 may receive either a Pfizer or Moderna vaccine for their second dose. There may be additional exceptions for some children ages 5 and older who are moderately or severely immunocompromised. Please see the Pediatric COVID-19 Vaccine Dosing Quick Reference Guide for more details.
The CDC Interim Clinical Considerations for the Use of COVID-19 Vaccines, allows for a different COVID-19 vaccine to be used in the following exceptional circumstances when FDA authorization requires that a vaccine from the same manufacturer be used. A different COVID-19 vaccine may be administered (at a minimum interval of 28 days between the first and second doses). A Vaccine Adverse Event Reporting System (VAERS) report is not required for these exceptional situations:
- Same vaccine not available
- Previous dose unknown
- Person would otherwise not complete the vaccination series
- Person starts but unable to complete a vaccination series with the same COVID-19 vaccine due to a contraindication
- AAP Pediatric COVID-19 Vaccine Dosing Quick Reference Guide
- CDC Transitioning from a younger to older age group
What are the vaccine recommendations for children and adolescents who are moderately to severely immunocompromised?
Children and adolescents with certain immunocompromising medical conditions or who are receiving treatments that induce moderate to severe immune suppression should be vaccinated according to the schedule outlined on Pages 3-5 of the AAP Pediatric Vaccine Dosing Quick Reference Guide.
Prior to and following COVID-19 vaccine administration, infection prevention measures should continue such as wearing a mask, physical distancing, and avoiding crowds and poorly ventilated indoor spaces, as immunocompromised individuals may still be at increased risk for COVID-19. Close contacts of immunocompromised individuals who are eligible should receive COVID-19 vaccination (series and additional doses) to provide additional protection.
Information on immunization and immunocompromised children and adolescents can be found in the:
- Red Book: Immunization and Other Considerations in Immunocompromised Children | Red Book® 2021 | Red Book Online | AAP Point-of-Care-Solutions
- CDC Clinical Considerations
- CDC COVID-19 Vaccination for People Who are Moderately or Severely Immunocompromised
What are the vaccine recommendations for patients who previously received a dose of monovalent mRNA vaccine?
After completion of an initial COVID-19 vaccine series, some individuals, who have only received a monovalent dose or those who are immunocompromised may receive an additional dose. Please see the AAP Pediatric Vaccine Dosing Quick Reference Guide.
Experts continue to recommend that everyone get vaccinated and stay up-to-date, regardless of whether they’ve had COVID-19 in the past. COVID-19 vaccination provides stronger and longer duration of protection against future COVID-19 disease than recovering from natural infection alone. Individuals can get COVID-19 multiple times, especially as new strains circulate in communities.
Can I administer a COVID-19 vaccine to a patient who is currently sick with COVID-19?
COVID-19 vaccination should be deferred for patients with a current SARS-CoV-2 infection until they recover from their acute illness and the criteria to discontinue isolation has been met. Patients who are asymptomatic should receive COVID-19 vaccine following their recommended isolation period. This also applies to people who become infected with COVID-19 between their vaccine series doses.
Individuals who recently had SARS-CoV-2 infection and have concluded their isolation period may consider delaying COVID-19 vaccine by 3 months from symptom onset or positive test (if infection was asymptomatic). Studies have shown that increased time between infection and vaccination may result in an improved immune response to vaccination.
What is the difference between COVID-19 mRNA and protein subunit vaccines?
These vaccines use a newer technology where mRNA is wrapped in a coating (lipid nanoparticle) so it can enter our cells. The mRNA in the vaccine teaches our cells how to make copies of a spike protein. Once the spike protein is made, two things occur: (1) the cell breaks down the mRNA (instructions) and gets rid of them, and (2) the spike protein triggers an immune response inside of our bodies, which produces antibodies. These antibodies protect us from getting infected if the real virus enters our bodies.
Subunit vaccines include a part (protein) of the virus that best stimulates your immune system. Once your immune system recognizes the protein subunit, it creates antibodies and defensive white blood cells. If you later become infected with the COVID-19 virus, the antibodies will fight the virus. These vaccines often include an adjuvant to increase the body’s immune response.
COVID-19 Vaccine Research
Is it safe for pregnant or lactating women to receive COVID-19 vaccine?
Safety data have showed no major concerns reported in pregnant persons. Additionally, recent studies show that vaccination during pregnancy with a 2-dose mRNA COVID-19 vaccine series may help prevent COVID-19 hospitalizations in infants < 6 months of age. The CDC previously issued a Health Alert Network Advisory strongly recommending urgent action to increase COVID-19 vaccination before or during pregnancy as the benefits outweigh known or potential risks.
Guidance is also available from the American College of Obstetricians and Gynecologists (ACOG).
Does COVID-19 vaccine affect fertility or puberty?
Unfounded claims linking COVID-19 vaccines to infertility have been scientifically disproven. There is no evidence that the vaccine can lead to loss of fertility. While fertility was not specifically studied in the clinical trials of the vaccine, no loss of fertility has been reported among trial participants or among the millions who have received the vaccines since their authorization, and no signs of infertility appeared in animal studies. Similarly, there is no evidence that the COVID-19 vaccine affects puberty.
When is a vaccine recipient considered up to date?
An individual is up to date with their COVID-19 vaccines when they have received all doses recommended for them.
Side Effects and Safety Monitoring
Are there any safety concerns with the new technologies (mRNA and nanotechnology) being used in the development of the Pfizer-BioNTech and Moderna COVID-19 vaccines?
There are no known additional risks of mRNA vaccines or lipid nanoparticles. Live attenuated viral vaccines, such as measles vaccine, induce an immune response that is similar to natural infection. mRNA vaccines, on the other hand, simply give the body instructions to produce one very specific part of a virus – in this case the so-called spike protein – to then induce an immune response. Because mRNA is broken down very quickly in the human body, to do its work it needs to be able to get into our cells, and so it is wrapped in a lipid nanoparticle. Once it gets into the cells to deliver the instructions, the mRNA breaks down very quickly. It does not get into the nucleus of the cell, or into our genes. Since the new mRNA vaccines have been administered, their safety profiles are reassuring.
Since April 2021, rare cases of myocarditis and pericarditis have been reported in adolescents and young adults (under 30 years of age) following receipt of mRNA vaccines – most often following the 2nd dose. COVID-19 vaccination reduces patients’ risk of myocarditis caused by getting infected with SARS-CoV-2 and developing COVID-19 disease. Studies have shown that risk of myocarditis was up to 6 times higher post SARS-CoV-2 infection than post-mRNA vaccines. Post-vaccine myocarditis is milder, requiring shorter hospital stays (1-2 days) vs. myocarditis caused by SARS-CoV-2 infection which has been more severe requiring a hospital stay of 5 days on average. Pediatricians should consider myocarditis and pericarditis in adolescents or young adults with acute chest pain, shortness of breath, or palpitations and report any suspected cases post COVID-19 vaccination to VAERS. History of myocarditis of pericarditis after a dose of an mRNA vaccine is also listed as a precaution for future doses. CDC continues to monitor the situation and has created guidance for health care providers
Clinical Considerations: Myocarditis after mRNA COVID-19 Vaccines | CDC
What side effects are noted to date with COVID-19 mRNA vaccines (Pfizer-BioNTech and Moderna)?
The side effects have been similar to other routine vaccines- sore arm, redness, fatigue, fever, chills, headache, myalgia, and arthralgia. The side effects are temporary and mostly mild or moderate. Side effects may be worse after the second dose in some individuals. Anaphylaxis has been observed following receipt of COVID-19 mRNA vaccines but this has been rare. Extremely rare cases of myocarditis or pericarditis have been reported – most often in males between 12-39 years of age – and most often following the 2nd dose. Additional information on common side effects and rare adverse reactions can be found here:
Possible Side Effects After Getting a COVID-19 Vaccine | CDC
Selected Adverse Events Reported after COVID-19 Vaccination | CDC
What side effects are noted to date with the Novavax protein subunit vaccine? Are there any contraindications ?
Side effects similar to other vaccines, (such as fever, chills, tiredness, and headache) are more common after the second dose of the vaccine. Severe allergic reactions to vaccines are rare but can happen. Cases of myocarditis and pericarditis have been reported in people who received Novavax COVID-19 vaccine.
Novavax COVID-19 Vaccine should not be given to individuals with a known history of a severe allergic reaction (e.g., anaphylaxis) to any component of the Novavax COVID-19 Vaccine, Adjuvanted.
Are there any contraindications to receiving COVID-19 mRNA vaccines from Pfizer-BioNTech and Moderna?
CDC considers the following to be a contraindication to vaccination with both Pfizer- BioNTech and Moderna COVID-19 vaccines: Severe allergic reaction (eg., anaphylaxis) after a previous dose of an mRNA COVID-19 vaccine or any of its components, immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG]), and immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG)*
In persons who report a history of anaphylaxis to another vaccine (i.e., any other vaccine besides the Pfizer-BioNTech and Moderna COVID-19 vaccine) or injectable therapy, a risk assessment should be conducted to determine type of reaction and certainty of information. A small number of vaccine recipients have experienced anaphylaxis following receipt of the Pfizer vaccine. Consider observing people with the following medical histories for 30 minutes after COVID-19 vaccination to monitor for allergic reactions:
- Allergy-related contraindication to a different type of COVID-19 vaccine
- Non-severe, immediate (onset within 4 hours) allergic reaction after a previous dose of COVID-19 vaccine.
- Anaphylaxis after non-COVID-19 vaccines or injectable therapies
Patients who experience anaphylaxis following the first dose of COVID-19 vaccine should be counseled not to receive the second dose and referred to an allergist-immunologist for appropriate follow up.
Do we need to worry about an increase in MIS-C in kids receiving COVID-19 vaccine?
To date, MIS-C has not occurred following receipt of COVID-19 vaccine without SARS-CoV-2 infection. In fact, COVID-19 vaccine offers protection against MIS-C, as a recent study demonstrated that receipt of 2 doses of Pfizer-BioNTech COVID-19 vaccine is highly effective in preventing MIS-C in persons 12-18 years of age.
What is the safety testing that has been done on COVID-19 vaccines? How do we know it is safe long-term?
The safety follow-up for COVID-19 vaccines is essentially the same that it is for all vaccine trials. All vaccines are determined to be safe and effective before they are authorized or licensed.
Pediatric vaccine studies involve very close follow up and tracking of patient’s health status and medical care post vaccination (eg. monitoring side effects, medical visits, use of new medications or changes to previous medications, and other interactions post vaccination). All reported medical events are recorded and reviewed by the study team, sponsor, an independent safety monitoring board, an ethics committee, and the FDA. Children in these studies are often followed for one to two years post vaccination and their health status is monitored for vaccine safety.
Even after authorization or licensure, safety data are collected through Vaccine Adverse Event Reporting System (VAERS), Vaccine Safety Datalink (VSD), pharmacovigilance, and, for COVID-19 vaccines, through a system called V-SAFE. These programs collect information on an even larger number of persons who get vaccinated than can be collected during clinical studies.
Safety data beyond 2 years, is captured through studies performed post licensure. No licensed vaccines have been found to have an unexpected long-term safety problem, that was found only years or decades after introduction.
What vaccine safety surveillance programs are in place?
All COVID-19 vaccines approved and/or granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) and vaccines on the Recommended Child and Adolescent Immunization Schedule, including co-administered vaccines are monitored through robust FDA and CDC systems that monitor vaccine safety in the United States. This vaccine safety system includes the Vaccine Adverse Event Reporting System (VAERS), Vaccine Safety Data Link (VSD), Clinical Immunization Safety Assessment (CISA), and V-SAFE. These systems have proven that they work in picking up a safety signal for an extraordinarily rare complication with previously-available the Janssen COVID-19 vaccine. VAERS and VSD are specifically designed to monitor safety signals from simultaneous administration of multiple vaccines (ie co-administration). Pediatricians should share information with patients on VAERS
Changes are coming to V-SAFE on May 19th. At that time, those enrolled in V-SAFE will be unable to add new COVID-19 doses to their account, but may still access their account and review previous entries. The CDC is developing a new version of v-safe that will launch later this year and again allow users to share their post-vaccination experiences with new vaccines.
Pediatricians should share information with patients on VAERS and encourage registration in the new V-SAFE program (once available) during the vaccination visit.
Ensuring COVID-19 Vaccine Safety in the US | CDC
V-safe After Vaccination Health Checker | CDC
What do we know about the new SARS-CoV-2 variants and vaccine efficacy?
Multiple variants of SARS-CoV-2 have been documented in the United States and globally, since the start of the virus’ spread. Data show that effectiveness of vaccines may diminish over time; however, they are still effective in preventing hospitalization and death. The AAP continues to support COVID vaccination among the population as the best way to prevent severe morbidity and mortality from SARS-CoV-2.
American Academy of Pediatrics