The FDA’s abrupt decision to cancel next month’s vaccine advisory committee meeting is raising concerns about whether the U.S. will have enough of the vaccine for the next flu season.

The Food and Drug Administration was allowed to participate in the World Health Organization's meeting this week on updating influenza shots, officials for the U.N. agency said, despite an order by President Trump last month banning government employees from working with the WHO. The administration has granted some exemptions to the order.