https://www.scientificamerican.com/article/coronavirus-news-roundup-february-13-february-19/ > The items below are highlights from the free newsletter, “Smart, useful, science stuff about COVID-19.” To receive newsletter issues daily in your inbox, sign up here. > Why are SARS-CoV-2 infection rates and COVID-19 hospitalizations dropping so rapidly these days in the U.S.? A 2/17/21 story by Derek Thompson at The Atlantic reports that it’s a combination of better social distancing, increased mask-wearing, seasonality, a growing number of people in the U.S. who have developed antibodies after infection with the virus (15% to 30% of U.S. adults), and the growing number of people in the U.S. who have been vaccinated against COVID-19. “We’re accelerating toward a moment, sometime this spring, when half of American adults should have some kind of coronavirus protection,” Thompson concludes.