How the United States Beat the Variants, for Now

The country has managed to avoid a variant-fueled spike in coronavirus cases. Scientists say we were lucky.

On Dec. 29, a National Guardsman in Colorado became the first known case in the United States of a contagious new variant of the coronavirus. The news was unsettling. The variant, called B.1.1.7, had roiled Britain, was beginning to surge in Europe and threatened to do the same in the United States. And although scientists didn’t know it yet, other mutants were also cropping up around the country. They included variants that had devastated South Africa and Brazil and that seemed to be able to sidestep the immune system, as well as others homegrown in California, Oregon and New York. This mélange of variants could not have come at a worse time. The nation was at the start of a post-holiday surge of cases that would dwarf all previous waves. And the distribution of powerful vaccines made by Moderna and Pfizer-BioNTech was botched by chaos and miscommunication. Scientists warned that the variants — and B.1.1.7 in particular — might lead to a fourth wave, and that the already strained health care system might buckle.