Pfizer has reported clinical trial results showing its COVID-19 vaccine is safe and 100 percent effective in preventing illness in adolescents 12-15 years old. Yet questions remain on why kids should get vaccinated and when it will happen. Chemistry professor Jonathan Dattelbaum recently weighed in on how vaccinating kids can control the spread of coronavirus.

What’s the current state of testing for the Pfizer, Moderna, and Johnson & Johnson vaccines? 

Clinical trials for adults have been completed and evaluated for three vaccines in the United States. The Pfizer-BioNTech vaccine is authorized for people 16 years and older, while the J&J and Moderna vaccines are authorized for people 18 years and older. Pfizer-BioNTech and Moderna have already fully enrolled children 12 years old and up in trials to test their vaccines. All of the companies are actively recruiting or about to start recruiting younger children and infants as well. These trials will test the safety and effectiveness of vaccine doses that are likely to be diluted compared to the trials conducted in adults.

Why is it important to vaccinate kids from COVID-19? Does that need to happen to achieve herd immunity?  

The percentage of people that need to be vaccinated to achieve herd immunity is different for each disease. Estimates for Sars-CoV-2 (the virus that causes COVID-19) typically range from 70% to 85% of the population. This takes into account being protected either through vaccination or contracting the virus. People under the age of 18 make up about 22% of the U.S. population. This means that 100% of people 18 and over would need to be vaccinated to achieve about a 78% vaccination rate. Based on this, and some vaccine hesitancy being reported, it seems likely that getting kids vaccinated will be an important part of the solution to achieve herd immunity in the U.S. 

What do you think will be the practical effect of the Pfizer trial results?

The interim results released by Pfizer are very promising and provide further evidence to support the effectiveness and safety of this vaccine in younger teens. Depending on how quickly the Pfizer results are finalized and submitted to FDA, vaccinations for children 12 years and older could begin in earnest by early summer.

Why would we expect the vaccines to be safe for children?

Vaccines tend to be tested in adults first (18 years and older) and then teens (12 years and older), before being tested in younger children, infants, and pregnant women. The CDC and FDA have implemented many channels that allow for safety signal monitoring to be conducted to help quickly catch any safety issues that may arise.