According to a Reuters story, Pfizer Inc and its German affiliate BioNTech SE have begun developing the COVID-19 vaccine in children under the age of 12. On Wednesday, the first volunteers in the early-stage trial received their first injections, according to the study.

By early 2022, the organization expects to have expanded vaccines to the age group as a result of this program. Moderna Inc has launched a clinical trial of the vaccine in children earlier this month. Pfizer/pediatric BioNTech’s study, like Moderna Inc’s, will have children as young as six months old, according to the Reuters report.

In a 144-person Phase I/II trial, Pfizer/BioNTech expects to test the efficacy of their two-shot vaccine at three separate dosages – 10, 20, and 30 micrograms.

They expect to extend to a 4,500-person late-stage trial later, where they will assess the vaccine’s efficacy, tolerability, and immune response, most likely by testing antibody levels in the young subjects.

The firms expect to provide evidence from the trial in the second half of 2021, according to a Pfizer spokesperson.

Pfizer has been studying the vaccine in children aged 12 to 15 years old in the meantime. Castillo said the firm hopes to provide evidence from the trial in the coming weeks.

“Pfizer has extensive experience advancing vaccine clinical trials in children and babies, and the organization is dedicated to improving the health and well-being of children by thoughtfully planned clinical trials,” the company said.

In the United States, Pfizer’s vaccine has now been approved for use in people aged 16 and over. Clinical trials of the vaccine in children, whose immune systems can respond differently than adults, are also in the works.

According to public health authorities and infectious disease researchers, vaccinating infants is critical to ending the pandemic. Before infants may be vaccinated, the United States is unable to attain herd immunity, which occurs when enough individuals in a given population develop antibodies against a certain disease. According to official statistics, children make up about 20% of the population of the United States.

Pfizer announced in late January that the Covid-19 vaccine study in children aged 12 to 15 had reached its full enrollment target. The evidence in that cohort has “encouraged” the firm, which said it aims to share more information about the trial “soon.”

Pfizer made the announcement two days after announcing the start of an early-stage clinical trial of a new oral antiviral treatment that could be used as soon as Covid infection is detected.