Our pandemic is now being driven by a new virus, Delta, which is far more transmissible and has thus replaced the original Covid virus (now retrospectively named Alpha). The reason Delta has exploded is simply because it reproduces on a vastly more lavish scale than did Alpha; each Delta virus produces 1,000 times more offspring than Alpha.

With another Covid-19 surge in full swing, Vermonters have continued to raise concerns about breakthrough infections: cases among fully vaccinated people. But data on the vaccination status of people who have caught the virus remains hard to come by.

Over the last year and a half of this pandemic, I’ve spent a good deal of time reading, researching and writing about Covid. It almost seemed as though I’d spent my career getting ready for the pandemic. Medical school, a career as an academic surgeon, a lifelong researcher, and now a congenial group of fellow researchers with similar interests — it all came together as Covid crashed over the world.

Wearing masks to stop the spread of illness is commonplace in other countries, said Dr. Turner Osler, a research epidemiologist and an emeritus professor at the University of Vermont Larner College of Medicine. “In the United States, uniquely, we just turned it into some other thing,” he said.