By , WASHINGTON (Reuters) - The U.S. Food and Drug Administration’s chief had a “robust discussion” with the White House this week about the timeline for coronavirus vaccine approvals and believes vaccinating 20 million Americans this year is realistic, he said on Friday.FDA Commissioner Stephen Hahn declined to lay out a specific timetable for approval of the vaccine developed by Pfizer and BioNTech but said he hoped the regulator would make a decision this month.Many federal officials are expecting a vaccine approval within days of a Dec. 10 meeting of experts, though one FDA official...…By , WASHINGTON (Reuters) - The U.S. Food and Drug Administration’s chief had a “robust discussion” with the White House this week about the timeline for coronavirus vaccine approvals and believes vaccinating 20 million Americans this year is realistic, he said on Friday.FDA Commissioner Stephen Hahn declined to lay out a specific timetable for approval of the vaccine developed by Pfizer and BioNTech but said he hoped the regulator would make a decision this month.Many federal officials are expecting a vaccine approval within days of a Dec. 10 meeting of experts, though one FDA official...WW…