sciencemag.org
51%
953
Delta variant triggers dangerous new phase in the pandemic
Kai Kupferschmidt, Meredith WadmanScience’s COVID-19 reporting is supported by the Heising-Simons Foundation.When the coronavirus variant now called Delta first appeared in December 2020, in the Indian state of Maharashtra, it did not seem all that remarkable. But when it descended on New Delhi a few months later, its impact was devastating, with almost 30,000 cases reported daily in late April.