The agency’s overriding concern is that the holidays may accelerate the spread of the virus, C.D.C. officials said. Older family members are at great risk for complications and death should they contract the virus.
New concerns about the virus have been reflected in air travel plans. United Airlines said recently that it expected Thanksgiving week to be its busiest period since the pandemic’s onset, but on Thursday it reported that bookings had slowed and cancellations had risen in recent days. American Airlines has slashed December flights between the United States and Europe as cases rise sharply on both sides of the Atlantic.