Sheppard Mullin is the latest Am Law 100 firm to tighten its vaccination and masking policies for in-office U.S. personnel and roll back a more comprehensive reopening, as the threat of the delta variant reverberates throughout the United States.

“A new wave of infections is sweeping the country. After a couple of quiet months, infections among our people—especially the unvaccinated—are on the rise,” Sheppard Mullin chairman Guy Halgren said in a firmwide memo on Aug. 10, adding that ”The consequences for our people have at times been serious. The CDC and state and local governments have all been adjusting their rules and guidance and we need to do the same.”