WASHINGTON — President-elect Donald Trump pledged Monday to keep the polio vaccine available throughout his presidency, but didn’t extend that protection to other vaccines, saying he expects his administration will look closely at safety — something the U.S. Food and Drug Administration already does before granting approval.

Trump’s comments came during an hour-long press conference where he hinted at trying to privatize the Postal Service and said he planned to file a lawsuit against a presidential preference poll published by The Des Moines Register that found him trailing Vice President Kamala Harris in the last days before the election.