According to a New York Times database, cases of COVID-19 across the country have dropped 21 percent in the last two weeks. About three-fourths of states are seeing sustained reductions in coronavirus cases. And in the last few days, the University of Washington’s Institute for Health Metrics and Evaluation, whose model is used by many health agencies for planning, projected that new cases in the U.S. would decline steadily from here forward. But many experts are worried that our cases will surge again due to new variants of the coronavirus, similar to what has happened in Great Britain, South Africa and Brazil. So far, the main variant has been found most often in Southern California and Florida. At this point, COVID-19 cases in those areas are still falling. But since the vaccines appear effective against coronavirus variants, health officials are trying to vaccinate as many people as possible as quickly as possible.