This story was updated March 26, 2021.
Mar. 17, 2021 -- Pfizer and Moderna have both launched clinical trials for coronavirus vaccines in children 6 months to 11 years old.
Pfizer, in a statement on its website, said the three-phase trial will enroll more than 4,600 children. Babies younder than 6 months may be evaluated later, the company said. Results could be available later this year and, if all goes well, the company said it could see FDA authorization early in 2022.
Study participants will be separated into three groups: Those 6 months to 2 years old, those between 2 and 5, and those from 5 through age 11. The children will receive first a 10 microgram dose before progressively receiving higher doses, CNBC reported. Participants also have the option to take 3 microgram doses. Adults receive two shots of 30 micrograms per dose.
Moderna, which is already conducting trials on children 12- to 17-years-old, aims to enroll 6,750 younger children in the United States and Canada in the KidCOVE study, Moderna said this month in a news release.
In the first part of the trial, children 6 months to 1 year will be given two vaccine doses of 25, 50, or 100 micrograms 28 days apart. Children 2 to 11 years will receive 50 or 100 micrograms 28 days apart.
Researchers will use data from the first part of the trial to decide what size dose to use in the second part. In the second part, some children will receive a saline placebo.
Currently, no vaccines are given to children in the United States.
In January, Moderna CEO Stéphane Bancel said results of the clinical trials on younger children probably would not be available until 2022.
Moderna is conducting the study with the National Institute of Allergy and Infectious Diseases and the Biomedical Advanced Research and Development.
“We are pleased to begin this Phase 2/3 study of mRNA-1273 in healthy children in the U.S. and Canada and we thank NIAID and BARDA for their collaboration,” Bancel said in the news release. “This pediatric study will help us assess the potential safety and immunogenicity of our COVID-19 vaccine candidate in this important younger age population.”
Severe illness and death because of COVID-19 are rare among children, the American Academy of Pediatrics says.
As of March 11, more than 3.28 million children have tested positive for COVID-19 since the onset of the pandemic, about 13% of all U.S. cases, the AAP said. That statistic was based on information from health department websites of 49 states, New York City, the District of Columbia, Puerto Rico, and Guam.
The AAP said 266 children had died of coronavirus-related causes, based on information from 43 states, New York City, Puerto Rico, and Guam.
Correction: An earlier version of this story gave the incorrect dosage levels for the Pfizer vaccine. It is given in micrograms, not milligrams.