Washington: The Pfizer-BioNTech Covid vaccine is safe and effective for children aged six months to under five years when given in three doses, the companies said in a statement Monday. The announcement comes as the US Food and Drug Administration (FDA) is planning meetings in the coming weeks to weigh authorising Covid vaccines among the youngest children, the only age group who are not yet eligible in most countries, a source of concern to many parents. Pfizer-BioNTech evaluated three doses, given at three micrograms, in a clinical trial and found the vaccine evoked a strong immune response. Side effects were similar in the vaccine and placebo groups. Vaccine efficacy was 80.3 percent, according to a preliminary estimate. “We are pleased that our formulation for the youngest children, which we carefully selected to be one-tenth of the dose strength for adults, was well tolerated and produced a strong immune response,” said Pfizer CEO Albert Bourla in a statement. “We look forward to soon completing our submissions to regulators globally with the hope of making this vaccine available to younger children as quickly as possible, subject to regulatory authorization,” he added. The FDA has tentatively scheduled three dates in June where experts will meet and likely decide whether to authorize the Pfizer Covid vaccine for under-fives and the Moderna vaccine for under-sixes, which is given as two shots of 25 micrograms. The agency was originally set to evaluate the Pfizer vaccine given as two doses in February, but data showed it did not provoke a strong enough immune response in children aged two to four. The FDA then asked to see data for a third shot.