For parents and grandparents considering the advantages and disadvantages of vaccinating young children, there is a small amount of data and an evolving context of unknowns that contribute to formulating a position. Arriving at a conclusion is closely connected to how one weighs the various facets.
COVID Vaccine Safety In Young Kids
Pfizer and Moderna provided preliminary on safety and efficacy to obtain Emergency Use Authorization from the FDA. The Pfizer vaccine trial included about 1700 children 5 and under who received two doses three weeks apart and a third dose at least two months after the second dose (1). The Modern a vaccine trial included 6700 children under years old who received 2 doses of the vaccine 4 weeks apart (2). In both trials, the vaccines were well tolerated with mainly mild to moderate adverse effects and no cases of conditions involving inflammation of the heart muscle.
COVID Vaccine Efficacy In Young Kids
The Pfizer vaccine data in children 5 and under showed 80% efficacy in preventing symptomatic infection based on 10 cases identified a week after the third dose. Of note, this study took place before the Omicron variant was widespread. The Moderna vaccine data was obtained during the Omicron wave and showed 51% efficacy against symptomatic infection among children ages 6 months to 2 years and 37% efficacy among children 2 to 5 years.
SUMMARY AND COMMENTARY
This is a gray area with limited data. The direct benefits and risks of the vaccine to a child are both likely small. My soft leaning is toward vaccination because of the combination of these small benefits to kids and larger benefits to a community.
COVID is ubiquitous and the choice for kids is between being exposed to COVD with or without a previous vaccine. I suspect that the long-term risks of the virus and vaccine are not significant but there is no longitudinal data on either. Also, the small long-term risk of the virus is likely as great or greater than the long-term risks of the vaccine.
The future benefit on children under 5 versus the variants to come is small to moderate. Adult vaccine trials showed a higher efficacy because they were created to match the original virus. The virus has mutated and the vaccine is less effective in preventing symptomatic infections in adults and children. With future variants, this efficacy will likely be further reduced. The main benefit of the vaccine is in preventing severe disease. Because severe disease is uncommon in kids under 10 this benefit is smaller. Another benefit of broader vaccination to include young children is reduced community spread. This benefit is magnified in settings where other preventive measures (masking, distancing, ventilation) have been abandoned. Without preventive measures in place and with a more transmissible variant, it is easier for one person to infect many others.
And lastly, for a bigger perspective, we have about 400 trillion viruses in our bodies. Estimates suggest that there are about 200 known types of viruses in the human body but less than 1% of all viruses in the human body are known. People who live together share about 25% of their virome due to casual contact such as sharing food, tables, and sinks (3,4). As we hyper-focus on the implications of exposure to a single virus or vaccine, it is helpful to broaden our lens and appreciate the myriad of changes that occur in our virome when we travel, welcome friends in our home, enter a new classroom, or visit a store.
1. Pfizer-BioNTech COVID-19 Vaccine Demonstrates Strong Immune Response, High Efficacy and Favorable Safety in Children 6 Months to Under 5 Years of Age Following Third Dose
https://www.pfizer.com/news/press-release/press-release-detail/pfizer-biontech-covid-19-vaccine-demonstrates-strong-immune
2. Moderna Announces Its Covid Vaccine Phase 2/3 Study In Children 6 Months To Under 6 Years Has Successfully Met Its Primary Endpoint
3. Viruses Can Help Us As Well As Harm Us
4. There Are More Viruses Than Stars In The Universe
https://www.nationalgeographic.com/science/article/factors-allow-viruses-infect-humans-coronavirus
Bradford Rabin MD provides concierge care for patients in the San Francisco Bay Area including Palo Alto, Menlo Park, Los Altos, Woodside, and Portola Valley.
Our concierge medicine practice focuses on exercise, nutrition, and longevity medicine to provide the best primary care concierge medicine. Primary care concierge medicine practices take care of smaller groups of patients and have the bandwidth to focus on the individual drivers for health span with personalized approaches to preventive care including wearable devices to optimize each person’s metabolism and innovative cancer techniques to identify early-stage disease.