American pharmaceutical Pfizer and its German partner BioNTech SE have started the clinical trials of its COVID-19 vaccine in children under 12, reported Reuters.

Pfizer spokesperson Sharon Castillo told Reuters that the first volunteers in the early-stage trial were given their first injections on Wednesday.

According to the Reuters report, with this initiative, the company hopes to expand vaccination to that age range by early 2022. Earlier this month, Moderna Inc also started a clinical trial of the vaccine in children. And like Moderna Inc, Pfizer/BioNTech's pediatric trial will involve children as young as 6 months.

As per the report, Pfizer and BioNTech initially are planning to test the safety of their two-shot vaccine at three different dosages - 10, 20 and 30 micrograms - in a 144-participant Phase I/II trial.

Later, they plan to expand to a 4,500-participant late-stage trial in which they will test the safety, tolerability and immune response generated by the vaccine, likely by measuring antibody levels in the young subjects.

Sharon Castillo said that the companies hope to have data from the trial in the second half of 2021. He also added that Pfizer has been testing the vaccine in children from age 12 to 15. The company expects to have data from that trial in the coming weeks.