Did any NPI public health did work sustainably? Anywhere?

This was when you had to be vaccinated and test negative before boarding a flight. None of it worked.

“Despite all the intervention measures that the U.K. had in place to try to stop people with the illness getting on flights to the U.K., almost every single plane we tested contained the virus, and most of the terminal sewers, too,” said researcher Davey Jones, a professor in the School of Natural Sciences at Bangor University in Wales.

“That might have been because people developed symptoms after testing negative; or were evading the system, or for some other reason,” Jones said in a university news release. “But it showed that there was essentially a failure of border control in terms of COVID surveillance.”

Source: Study of airplane wastewater shows COVID-19 travel restrictions failed – UPI.com

Unique for public health research – hah hah – they even had a control group of sorts:

During the study period, on March 18, 2022, a requirement that unvaccinated passengers get tested for COVID-19 before departure and two days after arrival was lifted. Researchers saw little difference in the wastewater before and after that date.

Coldstreams