Moderna this week began enrolling children as young as 6 months in a trial of its COVID-19 vaccine, opening a new front in the fight against the pandemic.

Called KidCOVE, the study plans to enroll about 6,750 healthy children under age 12 at sites in Canada and the United States — including Children’s Hospital of Philadelphia (CHOP).

“CHOP has not yet started to enroll patients and will work with Moderna to do so safely over the coming weeks,” hospital spokesperson Dana Bate said in a email.

Moderna, which has an online survey that parents can fill out to check their children’s eligibility, is collaborating with the National Institutes of Health on the trial, the first to test a COVID-19 vaccine in children under 12. Moderna, as well as Pfizer and Johnson & Johnson, are also conducting pediatric trials for children age 12 and up.

Since Moderna’s highly effective two-shot vaccine was approved for emergency use in December, more than 53 million doses have been administered in the U.S. to people age 18 and older.

Children generally get mild or asymptomatic COVID-19 infections, although in very rare cases, they may develop a dangerous inflammatory syndrome. Scientists are still evaluating whether vaccinated people can be asymptomatically infected and spread the disease.


“This pediatric study will help us assess the potential safety and immunogenicity of our COVID-19 vaccine in this important younger age population,” Moderna CEO Stephane Bancel said in a news release.

The first part of the new study is designed to evaluate whether doses lower than the 100 micrograms approved for adults should be used in children and infants. The 28-day interval between shots will be the same as for adults.

In the second part of the the trial, enrollment will be expanded to compare the best pediatric dose against a placebo. The children will be followed for 14 months, with as many as seven visits to the study site. Parents will use a smartphone app to report any symptoms of COVID-19 that develop in the children.

The American Academy of Pediatrics endorsed the idea of expanding vaccine testing to children after Pfizer’s two-shot COVID-19 vaccine became the first to get U.S. regulators’ approval in December.