To many parents’ dismay, a new report from the US Centers for Disease Control and Prevention found that the Covid-19 vaccine is less effective against the Omicron variant for children ages 5 to 11 than for older children and adults. Two doses of the Pfizer/BioNTech vaccine reduced the risk of Omicron infection by 31% among children 5 to 11 years old, compared with 59% among those 12 to 15.
Vaccinated children ages 5 to 11 were about 46% less likely to need medical treatment for Covid-19 from an urgent care clinic or emergency department, compared with unvaccinated children, a previous CDC study found. That study also revealed vaccination appears to protect against severe disease: Out of almost 1,700 total admissions, there were 59 unvaccinated children in this age group admitted to the hospital with Covid-19, compared with just two who were vaccinated.
Why is this happening? How worried should parents and caregivers be? Do the new data mean they should keep masks on their kids in school and avoid indoor extracurriculars? What are implications for kids with underlying medical conditions? And what’s the update for kids under 5?
To guide us through these questions, I spoke with CNN Medical Analyst Dr. Leana Wen, an emergency physician and professor of health policy and management at the George Washington University Milken Institute School of Public Health. She is also author of “Lifelines: A Doctor’s Journey in the Fight for Public Health” and the mother of two young children.
CNN: Why do you think the Covid-19 vaccine may be less effective in younger children than older children?
Dr. Leana Wen: First, I want to urge everyone to keep these data in perspective. The vaccines in younger children still appear to protect against severe illness, and that’s the most important reason we get vaccinated: to prevent hospitalization and death.
Scientists don’t know as to why the vaccine shows less effectiveness in younger kids compared with older kids and adults. The most likely explanation is that it’s related to dose. The dose of the Pfizer vaccine given to 12-year-olds and above is 30 micrograms, compared with 10 micrograms for those ages 5 to 11. The higher the dose, the higher the possible side effects – that’s why a lower dose was chosen for the younger group. It’s possible that this lower dose resulted in less effectiveness.
There are some other explanations of the data. It’s possible that by the time of the Omicron infection, so many young children had been exposed to Covid-19 that the effect of vaccination was reduced. It’s also worth noting that effectiveness against symptomatic infection also wanes in adults, and that’s why the CDC recommends the booster dose for all those 12 and older. Still, we can see that vaccination is still protective in this younger age group against severe illness.
CNN: How worried should parents and caregivers be? Should they rethink their decisions to remove masks and allow their kids to participate in extracurricular activities and indoor playdates?
Wen: The decreased protection is against symptomatic illness. It’s certainly disappointing, but I don’t think this alone should make them second-guess their decisions about removing masks and resuming extracurricular activities.