Local monitoring of SARS-CoV-2 variants in two large California counties in 2021 oleh Noah Kojima, Eugenia Khorosheva, Lauren Lopez, Mikhail Hanewich-Hollatz, J. Cesar Ignacio-Espinoza, Matthew Brobeck, Janet Chen, Matthew Geluz, Victoria Hess, Sophia Quasem, Nabjot Sandhu, Elias Salfati, Maria Shacreaw, George Way, Zhiyi Xie, Vladimir Slepnev, Jeffrey D. Klausner