A healthcare worker prepares a vaccine against Pfizer’s coronavirus disease (COVID-19) in Los Angeles, California, on January 7, 2021.
Lucy Nicholson | Reuters
Pfizer said it has started a clinical trial testing its Covid-19 vaccine in healthy children ages 6 months to 11 years, a crucial step in gaining federal regulatory clearance to begin vaccinating young children and controlling the pandemic.
The first study participants have already received their vaccines, which were developed in partnership with German drugmaker BioNTech, New York-based Pfizer announced Thursday. It intends to enroll 144 children in the first phase.
For the first phase of the trial, the company will identify the preferred dosage level for three age groups: 6 months to 2 years, 2 to 5 and 5 to 11 years. Children will start with a 10-microgram dose of the vaccine before progressing to higher doses, Pfizer said. Participants also have the option of taking 3-microgram doses. The Covid vaccine for adults requires two injections containing 30 micrograms per dose.
The researchers will then evaluate the safety and effectiveness of the selected dose levels in the next phase of the trial, and participants will be randomly selected to receive the vaccine or a placebo, the company said. After a six-month follow-up, children who received a placebo will have a chance to receive the vaccine, he said.
“Pfizer has extensive experience in advancing infant and child vaccine clinical trials and is committed to improving the health and well-being of children through carefully designed clinical trials,” the company said in a statement.
Pfizer’s vaccine has already been licensed for use in the US in Americans 16 years of age and older. Clinical trial studies testing the vaccine in children, whose immune systems may respond differently from adults, have yet to be completed.
Vaccinating children is crucial to ending the pandemic, public health officials and infectious disease experts say. The US is unlikely to achieve herd immunity, or when enough people in a given community have antibodies to a specific disease, until children can be vaccinated. Children make up about 20% of the US population, according to government data.
In late January, Pfizer said it had fully enrolled its Covid-19 vaccine trial in children ages 12-15. The company said Thursday that it is “encouraged” by the data from that cohort and said it hopes to share additional details about the trial “soon.”
Moderna, which also has a licensed vaccine in the US, said on March 16 that it had begun testing its vaccine in children under 12 years of age. Moderna began a study in December that evaluated children ages 12 to 17.
Johnson & Johnson plans to test its single-shot vaccine in infants and even newborns, after first testing it in older children, according to The New York Times.
White House chief medical adviser Dr. Anthony Fauci told a House committee earlier this month that the United States could begin vaccinating older children against Covid-19 this fall, while older children Elementary school children can start getting their shots early next year.
Pfizer’s announcement comes two days after it said it began an early-stage clinical trial of an experimental oral antiviral drug that could be used at the first sign of Covid infection.
Health experts say the world will still need a variety of drugs and vaccines to end the pandemic, which has infected more than 30 million Americans and killed at least 545,282 in just over a year, according to compiled data. by Johns Hopkins University.