Even as coronavirus cases slide nationally, Harvard experts are warning the public to keep its guard up because more highly transmissible variants are likely to reverse that decline in the weeks to come, with one recently arrived strain already accounting for 10 percent of cases in Florida.
Atul Gawande, professor of surgery at Harvard Medical School and Cynthia and John F. Fish Distinguished Chair in Surgery, Brigham and Women’s Hospital, said that recent actions in Iowa, North Dakota, and Wisconsin to relax mask mandates are coming too soon despite cases declining nationally to just 91,000 a day last week from an early January peak of more than 300,000 new cases per day.
Gawande, on a conference call with reporters Tuesday, cited a study released over the weekend by researchers from the University of California, Scripps Research Institute, and the University of Arizona that performed a genetic analysis of viral samples across the country in search of a fast-spreading strain that has become dominant in the U.K. They found that the strain, referred to as B.1.1.7, appeared in U.S. samples as early as late November and has spread to 30 states. They also found that the variant increases transmission rates by between 35 percent and 45 percent, causing cases to double every week and a half. The researchers projected that it will become the dominant strain here in March.
Though the U.S. vaccination campaign is forging ahead, with 32 million Americans having received at least one dose, Gawande said the speed of the new variant’s spread appears almost certain to outstrip that of the vaccination effort. In Israel, he said, 50 percent of the population has been vaccinated, but with the U.K. variant at 50 percent of cases, hospitalizations continue to rise. Unless mitigation efforts here are stepped up to counter the new strain’s increased infectivity, he said, a now-familiar pattern can be expected: a spike in cases followed within weeks by a jump in hospitalizations, then a surge in deaths.