coronavirus vaccine in children under 12, an early sign of the next stage of the global immunisation campaign."Together with our partner BioNTech, we have dosed the first healthy children in a global Phase 1/2/3 continuous study to further evaluate the safety, tolerability, and immunogenicity of the Pfizer-BioNTech COVID-19 vaccine," the company said in a statement to news agency AFP."We are proud to start this much-needed study for children and families eagerly awaiting a possible vaccine option," the US drugmaker added.According to details posted on the site clinicaltrials.gov, the company is testing three different dosing levels - 10, 20 and 30 micrograms - in a 144-participant Phase I/II trial for use in this age group, with hopes of.