AIIMS Director Dr Randeep Guleria has said that drugmakers AstraZeneca and Bharat Biotech are conducting studies to determine safe and effective doses for children. "If we really need to control the pandemic and have children back to school and be comfortable with that, we will have to look for vaccines which are for children," Dr Guleria told NDTV. AstraZeneca and Bharat Biotech's Covishield and Covaxin vaccines are being used in the country's inoculation drive against the coronavirus. Dr Guleria's remarks came on a day when pharma companies BioNTech-Pfizer declared that their vaccine trials showed 100 per cent efficacy against the coronavirus in children aged between 12 and 15. They are planning to get approval for the vaccine's use in the United States on children under 15.