New York City, 20 September 2021 (dpa-AFX/MIA) - Pfizer Inc. (PFE) and BioNTech SE (BNTX) announced positive results from a pivotal trial of their Covid-19 vaccine in children 5 to 11 years. The results are the first from a pivotal trial of any Covid-19 vaccine in children under 12 years of age. Meanwhile, Topline readouts for the other two age cohorts from the trial - children 2-5 years of age and children 6 months to 2 years of age - are expected as soon as the fourth quarter of this year. Phase 2/3 trial showed a favourable safety profile and robust neutralizing antibody responses in children 5 to 11 years of age using a two-dose regimen of 10 µg administered 21 days apart, a smaller dose than the 30 µg dose used for people 12 and older, the companies said in a statement. The antibody responses in the participants given 10 µg doses were comparable to those recorded in a previous Pfizer-BioNTech study in people 16 to 25 years of age immunized with 30 µg doses. The data from the Phase 2/3 study, which is enrolling children 6 months to 11 years of age, was for 2,268 participants who were 5 to 11 years of age and received a 10 µg dose level in a two-dose regimen. In the trial, the SARS-CoV-2-neutralizing antibody geometric mean titer or GMT was 1,197.6, demonstrating strong immune response in this cohort of children one month after the second dose. This compares well to the GMT of 1146.5 from participants ages 16 to 25 years old, used as the control group for this analysis and who were administered a two-dose regimen of 30 µg. In addition, the Covid-19 vaccine was well tolerated, with side effects generally comparable to those observed in participants 16 to 25 years of age. The companies plan to share these data with the US Food and Drug Administration (FDA), European Medicines Agency (EMA) and other regulators as soon as possible.