https://www.siliconvalley.com/2021/07/29/covid-resurgence-shuts-down-twitters-bay-area-offices/

Twitter has reversed its re-opening of offices in San Francisco and New York as a resurgent coronavirus sows fear and uncertainty in the Bay Area and across the U.S.

The San Francisco social media giant has put any future re-openings on hold, citing new guidance from the U.S. Centers for Disease Control, and the “current conditions” that have seen the virulent Delta variant of COVID-19 boosting infections and hospitalizations.