FAU Expert on COVID-19 Boosters and Vaccines for Children Ages 5-11

COVID-19, Boosters, Vaccines, Children, Shots, Pandemic, CDC, FDA, Frequently Asked Questions, FAU Expert, Medicine, Public Health

By gisele galoustian | 11/3/2021

Florida Atlantic University’s Joanna Drowos, D.O., M.P.H., M.B.A., associate chair of the Department of Integrated Medical Science, an associate professor of integrated medical science, and a practicing physician at the Marcus Institute for Integrative Health at FAU Medicine, within  the Schmidt College of Medicine , provides answers to some of the most frequently asked questions regarding the COVID-19 boosters and vaccines for children ages 5 to 11.

Drowos is board certified in preventive medicine, family medicine and medical quality. Prior to joining FAU, she served as the center medical director of the Riviera Beach Health Center of the Palm Beach County Health Department. At the health department, Drowos participated in the care of the county’s medically underserved populations addressing various infectious diseases such as HIV/AIDS and tuberculosis. She also served as the director of medical education for the Palm Beach County Health Department’s Preventive Medicine Residency Program from 2009 to 2013.

  1. Who is eligible for a booster shot?  

For all adults over the age of 18 who received one dose of the Johnson & Johnson (J&J) vaccine, a booster shot is recommended at least two months after that dose. If you completed your second dose of either the Pfizer-BioNTech or Moderna vaccine at least six months ago and meet any of the following conditions you are eligible for a booster: age 65 and older, ages 18 to 64 with an underlying medical condition that increases the likelihood of COVID-19 complications (e.g. cancer, dementia, diabetes, heart disease, HIV), are over 18 and live or work in a long-term care facility, homeless shelter, prison or other congregate setting, or are frontline personnel with additional exposure due to their job (e.g. frontline health care workers, teachers, supermarket staff and mass-transit employees).

  1. Are the boosters the same as the original vaccine?

The booster doses of the Pfizer-BioNTech, Moderna and J&J vaccine are the identical composition as the original doses provided. The Moderna COVID-19 single booster dose is half of the dose administered for a primary series dose. The Pfizer-BioNTech and J&J boosters are given at the same dose as the initial series.  

  1. Is it safe to get a booster dose of a COVID-19 vaccine?

Safety data supports that the COVID-19 vaccines are safe and efficacious. In trials, side effects from the booster were the same as those seen after the original doses of the vaccines, including injection site pain, fatigue, headache, muscle aches and joint pain. No serious adverse events or serious safety concerns have been reported.

  1. Why would I “mix and match” my vaccine types?

As we have learned more about the vaccines, you may have a preference to receive one vaccine type over another. Mixing and matching also makes it easier to get a booster if you don’t have access to the original vaccine you received. There also is preliminary data from a new study funded by the National Institutes of Health (NIH) showing that people who were boosted with a shot different from their original vaccine saw one measure of immune response, a spike in antibody levels. In particular, J&J vaccine recipients who were boosted with either the Pfizer-BioNTech or the Moderna vaccine saw an increase in antibody levels much higher than those boosted with the J&J vaccine. At the same time there were no safety concerns identified with this strategy.  

  1. Can I get a Moderna booster if I got a Pfizer vaccine?

Individuals who are eligible for a booster shot may choose which vaccine they receive as a booster dose. You may have a preference for the vaccine type that you originally received, or you may prefer to get a different booster. The United States Centers for Disease Control and Prevention’s (CDC) recommendations have been updated and now allow for this type of mix and match dosing for booster shots.

  1. Can I get a Moderna booster if I got a J&J vaccine?

In October, the Food and Drug Administration (FDA) authorized a J&J COVID-19 booster shot for all individuals over 18. The booster allows anyone who got the company’s initial one-shot to get an added dose of protection at least two months later, as well as a new “mix and-match” strategy that provides the option of choosing another company’s vaccine as a booster.

  1. At what age is a child eligible to receive a COVID-19 vaccine?

The Pfizer-BioNTech vaccine is currently available to anyone ages 12 and older. The FDA has now issued an Emergency Use Authorization (EUA) to allow the vaccine to be administered to children between the ages of 5 and 11. After the CDC Committee on Immunization Practices met and made a formal recommendation, the vaccine is now available to this age group. Clinical trials are ongoing to evaluate the safety and efficacy of the Moderna vaccine in children ages 6 months to 18 years old, and for the Pfizer-BioNTech vaccine for children between the ages of 6 months and 5 years old.

  1. How well does the COVID-19 vaccine work to protect children from infection?

The effectiveness data to support the EUA in children down to 5 years old is derived from a global ongoing randomized, placebo-controlled trial involving approximately 4,700 children ages 5 to 11. The data collected comes from the U.S., Finland, Poland and Spain. Children in the vaccine group received two doses of the Pfizer-BioNTech COVID-19 vaccine with 10 micrograms of messenger RNA in each dose. The FDA compared the immune response of 264 participants from this study to 253 participants ages 16 to 25 years old who received two higher doses of the vaccine in a previous study, which determined the vaccine to be effective in preventing COVID-19. The immune responses of the younger aged participants were comparable to the older aged participants. The FDA also analyzed cases of COVID-19 occurring seven days after the second dose of the vaccine. This analysis included participants without evidence of prior infection with SARS-CoV-2, and revealed three cases of COVID-19 that occurred among 1,305 vaccine recipients and 16 cases of COVID-19 that occurred among 663 placebo recipients, revealing that the vaccine was 90.7 percent effective in preventing COVID-19 infection.

  1. Now that the Pfizer vaccine has been given the “green light” by the FDA and CDC for children ages 5 to 11, where can I get my child vaccinated?

Following approval of a vaccine regimen through the CDC’s advisory panel, vaccines will be available through pediatrician’s offices, pharmacies, hospitals, and other sites administering vaccines to children.

  1. Who should I talk to about vaccinating my child?

For questions related to vaccinating your child against COVID-19, contact your child’s pediatrician, or your state or local health department.

  1. Will the vaccine rollout for children ages 5 to 11 be different than it was for adults?

The federal government is coordinating a plan to engage pediatrician’s offices, pharmacies, hospitals, and other sites in administering vaccines to children. Federal health officials project that in the first week, 15 million doses of the two-shot regimen will be shipped.

  1. Is the Pfizer vaccine dosage the same for children and adults?

Just like with adults, the Pfizer-BioNTech COVID-19 vaccine for children ages 5 to 11 is administered as a two-dose primary series, three weeks apart. The difference is that children receive a lower dose (10 micrograms) of the same formulation used for individuals ages 12 and older (30 micrograms). The FDA also has approved that Pfizer-BioNTech can change the vaccine formulation to use a different buffer to maintain the vaccine’s pH (a measure of how acidic or alkaline a solution is) and stability. The new buffer, Tris, is commonly used in a variety of other FDA-approved vaccines and biologics, including children’s products. The FDA evaluated manufacturing data to support the use of Pfizer-BioNTech COVID-19 vaccine containing Tris buffer and concluded that it does not present safety or effectiveness concerns. This new formulation is more stable at refrigerated temperatures for longer periods of time, permitting greater flexibility for vaccination providers.

  1. Do healthy children need to be vaccinated?

While children are much less likely to become severely ill from the coronavirus, without vaccination they are still at risk. It is difficult to predict which children will become ill or develop long-term symptoms following COVID-19 infection. Nearly 6.2 million children in the U.S. have tested positive for COVID-19, resulting in tens of thousands of hospitalizations and more than 500 deaths. Some children who had COVID-19 are now showing long-haul symptoms. Additionally, unvaccinated children can continue to spread COVID-19 at a rate similar to that spread by adults. If there are younger children not yet eligible for vaccination, having all individuals in the home who are eligible to receive a vaccine can offer them additional protection. Some populations are suggested to be at increased risk for severe illness from COVID-19, including children with medical complexity, with genetic, neurologic, or metabolic conditions, or with congenital heart disease. Similar to adults, children with obesity, diabetes, asthma or chronic lung disease, sickle cell disease, or immunosuppression also can be at increased risk for severe illness from COVID-19.

  1. What are the side effects and risks associated with vaccinating my child?

When the FDA reviewed the clinical trial data from Pfizer-BioNTech, none of the roughly 3,500 children who received the vaccine in clinical trials suffered a serious side effect related to receiving the shots. Most of the minor side effects reported are consistent with those experienced by adolescents and adults, including temporary pain at the injection site, headache, fatigue and low-grade fevers. Myocarditis, a type of inflammation of the heart, also has been observed following vaccination. An Israeli study published this month found that among 2.5 million vaccinated people ages 16 or older, 54 of them experienced myocarditis after receiving the vaccine — a rate of 2.13 cases per 100,000 people. Nearly all cases were mild or moderate and did not require hospitalization, with the greatest prevalence among men and boys ages 16 to 29. Symptoms include chest pain and difficulty breathing. The Pfizer-BioNTech studies among 5 to 11 year olds and 12 to 18 year olds showed there were no identified cases of myocarditis. This may be because the complication is so rare it was only identified after millions of people had been vaccinated. The known risks of COVID-19 illness and its related, possibly severe complications, such as long-term health problems, hospitalization and even death, far outweigh the potential risks of having a rare adverse reaction to vaccination, including the possible risk of myocarditis or pericarditis.

  1. How do we know that the COVID-19 vaccines are safe for children?

A study found kid-size doses of the Pfizer-BioNTech vaccine were 91 percent effective at preventing symptomatic COVID-19, developing antibodies as strong as those of teens and young adults who got regular doses, with similar or fewer side effects. The FDA considered the safety of the smaller doses in 3,100 vaccinated youngsters, along with the safety information from hundreds of millions of larger doses given to adults and teens worldwide. The small risk of myocarditis, seen mostly in teen boys or young men after the second dose, usually resolves quickly and poses less risk than serious COVID-19 infection. After intense scrutiny, U.S. health authorities concluded that the vaccine's benefits outweigh that small risk.

  1. My husband and I are both vaccinated, so why do we need to vaccinate our children?

While it is true that fewer children have been infected with COVID-19 compared to adults, children can still become infected and spread COVID-19 to others who become seriously ill or become very sick themselves. It is impossible to predict which children will become seriously ill or will go on to develop long-term COVID-19 symptoms. Vaccinating children also is an important tool to help stop the spread of the pandemic.

  1. Children aren’t affected as severely by COVID-19 as adults, so why should I vaccinate my child?

Vaccinating your child also can help keep them from getting seriously sick even if they do get COVID-19. In the U.S., COVID-19 cases in children ages 5 to 11 make up 39 percent of cases in individuals younger than 18. According to the CDC, approximately 8,300 COVID-19 cases in children ages 5 to 11 resulted in hospitalization. As of Oct. 17, 691 deaths from COVID-19 have been reported in the U.S. in individuals under the age of 18, with 146 deaths in the 5-to-11-year-old age group. Research also suggests disproportionately higher rates of COVID-19 in Hispanic and non-Hispanic black children than in non-Hispanic white children.

  1. How much do children actually contribute to the spread of COVID-19? Will vaccinating them make a difference?

Widespread vaccination is a critical tool that will help us to stop the spread of the pandemic. People who are fully vaccinated can resume the activities that they enjoyed prior to the pandemic. While it is true that fewer children have been infected with COVID-19 compared to adults, children can still become infected and spread COVID-19 to others who become seriously ill or become very sick themselves. In one study, children were transmitting the virus as frequently as adults. Early information shows that the vaccines may help keep people from spreading COVID-19 to others. They also can help to keep your child from getting seriously sick even if they do get COVID-19.

  1. Should I wait awhile before vaccinating my child to ensure that there are no long-term effects?

As with all other vaccines, serious side effects that could cause a long-term health problem are extremely unlikely following COVID-19 vaccination. Vaccine monitoring has historically shown that side effects generally happen within six weeks of receiving a vaccine dose.

  1. If my child already had COVID-19 should I still vaccinate him?

As in the case with adults, COVID-19 vaccines are recommended for children who were previously infected with the virus. While the antibodies that develop in response to a COVID-19 infection give some level of natural immunity, it is unclear how well natural immunity protects against new infection and for how long. Vaccines offer more certain protection and have undergone significant scientific scrutiny.    

  1. How does COVID-19 affect children?

Children and adults often experience similar symptoms of COVID-19, however children tend to have milder symptoms that seem more like a cold. Most children recover within one to two weeks. Possible symptoms can include fever and chills, cough that becomes productive, nasal congestion, new loss of taste or smell, discolored skin on the feet and hands, sore throat, nausea, vomiting, belly pain, diarrhea, muscle aches and pain, fatigue and severe headache. Some children become severely ill with COVID-19, developing pneumonia and respiratory distress. They might need to be hospitalized, treated in the intensive care unit or placed on a ventilator to help them breathe. Some children have gone on to develop multisystem inflammatory syndrome in children (MIS-C), a condition where different body parts become inflamed, including the heart, lungs, kidneys, brain, skin, eyes, or gastrointestinal organs. MIS-C can be serious, even deadly, but most children who were diagnosed with this condition have gotten better with medical care. 

  1. If my child is vaccinated will she still need to wear a mask around others?

Local regulations on the use of masks are likely to evolve as the COVID-19 pandemic evolves, even for vaccinated individuals. The CDC recommends considering five critical factors in making decisions about layering COVID-19 prevention strategies, which include: masking; 1) level of SARS-CoV-2 community transmission; 2) health system capacity; 3) COVID-19 vaccination coverage; 4) capacity for early detection of increases in COVID-19 cases; and 5) populations at increased risk for severe outcomes from COVID-19. As far as thinking of local decisions, the CDC recommends that fully vaccinated persons wear masks in public indoor settings in areas of substantial or high transmission. "Substantial" transmission is 50 to 100 cases per 100,000, or a positivity rate between 8 and 10 percent, and "high" transmission is 100 or more cases per 100,000 people or a positivity rate of 10 percent or higher. When there is a discrepancy, the CDC recommends using the higher metric. Fully vaccinated persons might consider wearing a mask in public indoor settings, regardless of transmission level, if they or someone in their household is immunocompromised or is at increased risk for severe disease, or if someone in their household is unvaccinated.  

  1. If my child is vaccinated are sleepovers okay? What about other social functions like birthday parties?  

There is evidence suggesting that events that lead to small and informal social gatherings, such as birthdays, and in particular, children’s birthdays, are a potentially important source in SARS-CoV-2 transmission. The decision on whether to let your child participate in sleepovers or social functions depends on factors including community transmission, as well as your personal COVID-19 risk tolerance. If your child or someone in your household is immunocompromised or is at increased risk for severe disease, or if community transmission in your area is substantial or high, these factors deserve consideration and may affect your plans. Virtual, outdoor or distanced activities can be an option where possible.  


The answers to these questions are not meant as medical advice. They are intended to provide information that during a pandemic can change as we learn more about the virus and the vaccines that have been and are being developed. The information provided is the best available as of Nov. 3. For questions about specific circumstances, consult with a physician.