Why has a COVID-19 vaccine not yet been approved for children younger than 12? NCSE Executive Director Ann Reid explains the factors involved.
Photo by Mufid Majnun on Unsplash.
Check out our entire series explaining the science involved in the coronavirus pandemic. Sign up to receive our coronavirus update each week.
As kids start heading back to school, there’s a lot of frustration over why vaccines that have proven overwhelmingly safe and effective for teenagers and adults have not yet been approved for children younger than 12 years of age.
Of course, there are some nuts-and-bolts reasons for the delay. For example, should babies get the same dose of the vaccine as adults? Probably not. But how much should the dose be reduced? Figuring that out takes time. Part of the reason for the delay is just plain math. Back in April 2020, we published an article about the steps involved in testing a vaccine. After the basic safety tests have been done, the next step is to recruit trial participants, give half of them the vaccine, and then wait for enough symptomatic infections to emerge to be able to distinguish whether the vaccinated group is less likely to be infected. One of the reasons the data on the effectiveness of vaccines in adults could be gathered so quickly is that the coronavirus was spreading like crazy at the time the trials were running. You can think of it as trying out galoshes in the middle of a torrential rainstorm — you’re going to know pretty quickly if they leak.
But children are much less likely to be infected by the coronavirus, and less likely to display symptoms if they are. At the height of the pandemic, in January 2021, 0-4-year-olds had a case rate of 147/100,000 and 5-11-year-olds had a case rate of 208/100,000, while 18-29-year-olds had the highest case rate of any age group at 571/100,000. Those numbers suggest that it would take 2-3 times longer for enough infections to be detected to determine whether the vaccines were working for the children.
Another crucial bit of math is this: for any vaccine, drug, or medical device, a very basic requirement is that the risk from the treatment be less than the risk from the disease it is designed to treat. And the risk of COVID-19 to children is very, very low. The difference in death rates is stark. Again, at the height of the pandemic, the weekly mortality rate was 0.02 deaths/100,000 for 0-4-year-olds, 0.00 for 5-11-year-olds, and 54.07 for adults older than 75. The elderly diagnosed with COVID-19 were over 2,000 times more likely to die of it than children diagnosed with it! In total, the number of children in the U.S. who have died of COVID-19 has been reported to be approximately 400. That’s 400 out of more than 600,000 deaths. Across all states reporting, children have accounted for between 0.0% and 0.22% of all deaths from COVID-19, with seven states reporting no childhood deaths at all.
The death of any child is a tragedy, and if any future child’s death can be prevented by vaccination, it’s of course highly desirable to vaccinate. But given the extremely low risk, the vaccine itself must be shown to be extremely safe. Like, really, really, really safe. As in, it not only doesn’t kill any children, but doesn’t even cause serious side effects in more than a minuscule number of young recipients. Being certain that the vaccine is that safe in children means larger and longer trials, and that takes time. However frustrating that wait may be, it’s important to wait for the evidence.
