The clamor for hard-to-get Covid-19 vaccines has created armies of anxious Americans who have resorted to hunting for leftovers on the fringes of the country’s patchwork vaccination system.

They haunt pharmacies at the end of the day in search of an extra, expiring dose. They drive from clinic to clinic hoping that someone was a no-show to their appointment. They cold-call pharmacies like eager telemarketers: Any extras today? Maybe tomorrow?

Some pharmacists have even given them a nickname: Vaccine lurkers…

“There are people who feel desperate, and this is what they end up doing,” said Dr. Ashish K. Jha, dean of the Brown University School of Public Health. “It’s ridiculous. It’s wholly unnecessary. There should be a way to do this that does not require us going down this path.”