Pfizer and Moderna are expanding vaccine trials for children aged 5-11

Report says Pfizer and Moderna are expanding vaccine trials for children aged 5-11 at the FDA's request

The Food and Drug Administration invites Pfizer and Moderna to expand trials of a COVID-19 vaccine in kids ages 5 to 11 as a precaution after rare side effects were discovered in some people under 30, the New York Times reports.

While most young adults have experienced the same side effects as adults — arm inflammation, fatigue, or headaches — very rarely, patients develop myocarditis, swelling of the heart muscle, and pericarditis, which is swelling of the lining of the heart.

The CDC said in June that most cases were in teens and young adults 16 or older. Most patients recovered quickly after receiving treatment.

Citing how rare reports are and the risk of severe symptoms of COVID-19, the CDC said it would continue to recommend the vaccine to anyone over 12 years old.

The FDA has asked Moderna and Pfizer to add 3,000 children ages 5 to 11 to their ongoing studies for that age group, for whom results are expected to come first.

Studies in children under 12 are more complex: Teens receive the same dose as adults, but researchers are testing smaller quantities in younger kids. The first results, expected in September, are from the 5 to 11-year-old age group.

The precautionary measure of adding thousands of participants to trials will increase the database and potentially allow researchers and public health officials to understand the infrequent side effects. Still, experts warn that it may also delay authorization for the use of the vaccine.

In the USA, children account for about 14% of all coronavirus cases in the country so far. And while young people are much less likely to become seriously ill than older adults, at least 344 children have died from COVID-19 in the United States alone, according to a count from the American Academy of Pediatrics.

So far in the United States, just under half of the population is vaccinated—with the highest rates, not surprisingly, among the elderly. According to the CDC, only a quarter of children ages 12 to 15 who got the Pfizer vaccine starting in May got their second dose. Adults are 16 and 17 years of age, about 37% were fully vaccinated.