'Goldilocks virus': Delta vanquishes all variant rivals as scientists race to understand its tricks

The variant battle in the United States is over. Delta won. Since late last year, the country has been overrun by a succession of coronavirus variants, each with its own suite of mutations conferring slightly different viral traits. For much of this year, the alpha variant — officially known as B.1.1.7 and first seen in the United Kingdom — looked like the clear winner, accounting for the majority of cases by April. In second place was iota, B.1.526, first seen in New York City. A few others made the rogue’s gallery of variants: gamma, beta, epsilon.