On June 18, the Centers for Disease Control and Prevention (CDC) endorsed the Advisory Committee on Immunization Practices’ recommendation that all children six months through five years of age should receive a COVID-19 vaccine. The Pfizer BioNTech vaccine has been approved for children six months through four years, and the Moderna vaccine for ages six months through five years.
Although it is rare for children to become seriously ill from COVID-19, they still can. In fact, more than 1,000 have died, more than 40,000 have been hospitalized and more than 8,500 have developed multisystem inflammatory syndrome in children (MIS-C), which can cause inflammation of internal organs and can be fatal.
Evan Anderson, MD, professor of pediatrics and medicine, and an infectious disease physician at Emory and Children’s Healthcare of Atlanta, was involved in the clinical trials testing vaccines for children six months to 11 years of age at Emory and Children’s. Here, he answers questions about the new vaccine approval for children five and under.
Q: What is the difference between the Moderna and Pfizer vaccines for young children? Why are experts saying that young children need two doses of the Moderna vaccine and three doses of Pfizer?
A: The vaccines are licensed based upon the ability of the vaccine to stimulate a similar immune response as that seen in young adults enrolled in Phase 3 clinical trials. The Moderna vaccine, in children six months to five years, generated a similar immune response to adults with the two-dose series. With Pfizer, three doses were needed in these infants and young children to generate a similar immune response.
Q: The Pfizer vaccine has been approved for children six months through four years, and the Moderna vaccine for ages six months through five years. Why the age difference?
A: In Pfizer, the clinical trial age ranges for the doses were set for six months through four years of age, while Moderna was six months through five years of age. This is an issue of how the clinical trials were designed that then impacted the FDA licensure of the vaccines. Five-year-olds have been able to get the Pfizer vaccine at a higher dose since late October 2021.
Q: Why should parents get their younger children vaccinated?
A: A substantial number of infections occur in these young children. We’re also seeing relatively large numbers of hospitalizations in children who are not vaccine eligible, and a relatively large number of deaths occurring in children in these age ranges.
Influenza is a useful marker against which to gauge the burden. When we compare COVID-19 with influenza, the number of deaths seen with COVID-19 each calendar year since the beginning of pandemic are similar to or greater than the burden of seasonal flu that we observed before the pandemic. And that is despite all these social interventions we’ve undertaken trying to prevent transmission to our youngest children. There were far fewer deaths of children from influenza during the past flu season than deaths of children from COVID-19 in the past year.
Also, if you consider diseases for which we routinely vaccinate our children, such as Hep A, varicella and rotavirus, COVID-19 far exceeds the burden of disease observed in the pre-vaccine era for each of those pathogens. And yet, parents routinely vaccinate their children against these diseases.
Q: What about newborns to six-month-olds, who are still too young to be vaccinated? What is the risk to them?
A: In general, it’s been demonstrated that when the pregnant mother receives a COVID-19 vaccine, this provides good protection against severe COVID-19 outcomes in the baby in the first six months of life, according to data that partly came out of Children’s Healthcare of Atlanta and Emory. This is probably due to antibody transfer through the placenta, and it also helps the mother by protecting her against COVID-19 and the risk of transmitting it to her baby as well. Children and family members in households with new babies should be vaccinated to protect the youngest infants.
Q: What are the possible side effects of the vaccine for children and how do those compare with the risks of children getting COVID-19?
A: The most common side effects of the vaccine are fever, chills and generally not feeling well. Local symptoms are pain, redness, soreness and tenderness at the site of the vaccination. In general, most of these vaccine side effects are less pronounced in children than in adults. Most of these side effect symptoms can be easily controlled with medications like Tylenol or Ibuprofen. The rate of fever is no different than that observed with a number of other vaccines that children get as part of their routine vaccination schedule.
Q: Do children who are vaccinated also have a lower risk of multisystem inflammatory syndrome in children (MIS-C)?
A: Very good data, in part out of Emory and Children’s, demonstrates that the COVID-19 vaccine is about 90 percent effective in preventing MIS-C.
Q: Will vaccinated kids still get COVID-19, but a milder version?
A: Vaccines do remain somewhat protective against acquiring COVID-19 in general, and also decrease the risk of serious disease and hospitalization. But vaccines are not perfect in terms of prevention, particularly with high exposure in the household, which is more likely to cause a breakthrough infection than from a more casual exposure.
Q: Will vaccinated kids pose less danger to their parents/grandparents/teachers?
A: There is some evidence in adults that the duration of symptoms and the amount of virus shed is lower in people who have received vaccines than those who have not. As such, it is fairly likely that the risk of transmitting the virus to others is lower, although that has not been studied in children.
Q: How protected are kids who have had COVID-19? Do they still need the vaccine?
A: Although the seroprevalence in some studies is fairly high in children who have had COVID-19, the immune response and breadth of immune response appears less robust than that observed after two doses of COVID-19 vaccination. As such, vaccination is likely to decrease risk of recurrent infection and may provide better cross-protection again current and future variants.
Q: How do we know vaccines are safe for young children?
A: We have been very involved in the clinical trials of children’s COVID-19 vaccines at Emory and Children’s Healthcare of Atlanta. These vaccines have been well studied and thousands of children have been involved in the clinical trials that provided data to support their licensure. The size of these trials is similar to the size of clinical trials of a number of other vaccines that have already been licensed.
We also have a wealth of experience from older children, five and above, as well as adults, related to COVID-19 vaccines that we typically don’t have when a vaccine first is approved in the youngest children. It’s a unique situation as hundreds of millions of doses have been given in the U.S. This should provide additional reassurance to parents.