COVID-19 vaccines arrive for under 5s

This past Friday, the United States (US) Food and Drug Administration (FDA) issued updates to its COVID vaccine recommendations, extending the Pfizer COVID-19 vaccine's Emergency Use Authorization to include children aged 6 months to 4 years while also extending the Moderna COVID-19 vaccine from ages 6 months to 17 years. The next day, the US Centers for Disease Control and Prevention (CDC) authorized both vaccines for their respective age groups. Since US states have been able to preorder vaccines in the past few weeks, many locales may be ready to vaccinate children aged 6 months and older as early as this week.

The Pfizer vaccine for ages 6 months through 4 years has had a rather bumpy road to approval. The first two doses of vaccine, which were all older children and adults required to demonstrate an immune response, did not elicit a sufficient immune response in this younger age group, necessitating the addition of a 3rd dose in the series. While the 3rd dose did elicit an immune response "comparable" to that of young adults, the number of cases among enrolled children was too low to permit rigorous analysis regarding the vaccine's effectiveness against infection or hospitalization. Pfizer has touted an 80% effectiveness rate for preventing COVID-19 infection after 3 doses, "[b]ut that 80 percent estimate was based on only 10 cases in a subset of 1,678 trial participants."

Moderna's vaccine has previously only been available for adults aged 18 and older, and the FDA  approved all three of its proposed new age groups on June 17: children aged 6 months to 5 years, children aged 6-11 years, and children and teens aged 12-17 years. For these groups:

• "Among participants 6 through 23 months of age...the vaccine was 50.6% effective in preventing COVID-19. Among participants 2 through 5 years of age...the vaccine was 36.8% effective in preventing COVID-19."
• Immune response was comparable in children aged 6-11 years to young adults, but there were not enough COVID-19 cases in this cohort to determine vaccine efficacy against infection and hospitalization.
• "[A]mong participants 12 through 17 years of age, the vaccine was 93.3% effective in preventing COVID-19."

All of these trials were conducted before omicron became the dominant COVID-19 strain, though the FDA and CDC are still encouraging parents to obtain the vaccine for their children, even if they previously had COVID-19 infection. All of these vaccine products are safe, and any level of protection against COVID-19 infection is better than none. Over 400 children under the age of 5 have died in the US from COVID-19 since the pandemic began, and Multisystem Inflammatory Syndrome in Children (MIS-C) afflicts 1 in every 3000-4000 children who get symptomatic COVID-19. Vaccination should help decrease COVID-19 outbreaks in schools and daycare centers, which have disrupted countless families' schedules over the past 2+ years.

Vaccine uptake is predicted to be low in the under-5-years age group, though, with a recent survey showing that only 18% of parents are planning to vaccinate their eligible children immediately with another 38% who are less certain and adopting a "wait and see" approach. The US state of Florida only ordered its vaccine supply for this age group late on Friday after initial statements from its governor regarding his opposition to the vaccine. Despite conflicting messages from government leaders and widespread parental concerns, family physicians can still help parents make well-informed vaccination decisions. Sharing information about COVID-19 infection's risks to children may help combat misinformation regarding a perceived "low" risk in this age group, and the US Federal Emergency Management Agency (FEMA) has a Coronavirus Rumor Control website that fact checks several common myths. This 2021 Lown Right Care article reviews "Helping Ambivalent Patients Make Healthy Decisions about COVID-19" using motivational interviewing. A recent Curbside Consultation discussed navigating when two parents disagree about vaccinating their child. Lastly, this 2016 AFP editorial provides evidence-based "Strategies for Addressing and Overcoming Vaccine Hesitancy" that ends by reminding us that "patients' ambivalence is your friend because it means that they have not closed their minds to vaccines."