DEAR DR. FOX: Thanks so much for the wonderful piece about wolf conservation that you penned recently. Barry Lopez was indeed a kindred spirit, and I just learned he passed away in December at age 75. But I do not put myself in the same league as David Mech, who is of the old school of wildlife management, opposing the push to have wolves protected under the federal Endangered Species Act. The gray wolf should stay protected under the Endangered Species Act and not be delisted, as is in process right now. FERRETS GIVEN EXPERIMENTAL VACCINEAbout 120 black-footed ferrets at the National Black-footed Ferret Conservation Center in Colorado were inoculated last spring and summer with an experimental SARS-CoV-2 vaccine.