Shubham Chandra, center, returning home to New York from Cancun, Mexico, takes an anonymous COVID tests for study purposes after arriving at Newark Liberty International Airport in Newark, N.J., Wednesday, Jan. 4, 2023. Chandra knows how dangerous the coronavirus can be: He lost his father during the pandemic. So when he cleared customs and saw people offering anonymous COVID-19 testing, he was happy to volunteer. (AP Photo/Seth Wenig)