flu

Passengers wearing masks walk by as a quarantine officer, center, monitors a thermography during a quarantine inspection at Kansai international airport in Osaka, western Japan, Wednesday, Jan. 22, 2020. Chinese health authorities urged people in the city of Wuhan to avoid crowds and public gatherings after warning on Wednesday that a new viral illness infecting hundreds of people in the country. Japan, South Korea, the United States and Taiwan have all reported one case each. All of the illnesses were of people from Wuhan or who recently had traveled there. (Kota Endo/Kyodo News via AP)

FILE - In this Jan. 4, 2020, file photo, a health surveillance officer monitors passengers arriving at the Hong Kong International airport in Hong Kong. On Friday, Jan. 17, 2020, the U.S. Centers for Disease Control and Prevention officials said they will begin screening airline passengers at three U.S. airports who traveled from Wuhan in central China, for a new illness that has prompted worries about a new international outbreak. (AP Photo/Andy Wong, File)

Yemeni prisoners gather during their arrival after being released by the Saudi-led coalition in the airport of Sanaa, Yemen, Thursday, Nov. 28, 2019. The International Committee of the Red Cross says over a hundred rebel prisoners released by the Saudi-led coalition have returned to Houthi-controlled territory in Yemen, a step toward a long-anticipated prisoner swap between the warring parties. (AP Photo/Hani Mohammed)

FILE - In this Feb. 7, 2018 file photo, a nurse prepares a flu shot at the Salvation Army in Atlanta. The U.S. winter flu season is off to its earliest start in more than 15 years. An early barrage of illness in the South has begun to spread more broadly, and there’s a decent chance flu season could peak much earlier than normal, health officials say. (AP Photo/David Goldman)

B.K. Morris, a nurse with MedStar Visiting Nurses Association, gives a flu shot to Secretary of Health and Human Services Alex Azar during a news conference in Washington. The flu forecast is cloudy and it's too soon to know if the U.S. is in for a third miserable season in a row, but health officials said Thursday, Sept. 26, 2019, not to delay vaccination. (AP Photo/Lauran Neergaard)