NEW YORK — Surges in COVID-19 cases last year coincided with the emergence of new SARS-CoV-2 variants, a new study has found.
Since its initial declaration as a pandemic in March 2020, SARS-CoV-2 has spread around the world, causing an estimated 129 million cases of COVID-19 and 2.8 million deaths, according to the Johns Hopkins University COVID-19 dashboard.