Aug 6 (Reuters) - JPMorgan Chase & Co (JPM.N) employees in the United States will be required to wear masks in public indoor settings and in common areas within its offices regardless of their vaccination status, the bank told staff in a memo on Friday. The resurgence of COVID-19 cases in the United States due to the Delta variant and new guidance from the U.S. Centers for Disease Control and Prevention (CDC), that requires fully vaccinated individuals to wear masks, have led companies to change their plans on vaccinations and masking. read more "Given that the CDC has stated more than 80% of counties across the U.S. have substantial or high community transmission rates, we will follow this guidance nationally for the time being," JPMorgan said in the memo seen by Reuters. Only fully vaccinated employees are allowed to attend large indoor employee events with 25 people or more. Unvaccinated staff will be required to complete routine rapid COVID-19 testing at least twice a week, according to the memo. Many of Wall Street"s biggest banks are sticking by their decision to make employees return to the office in the coming weeks, even as public health officials" warnings about the aggressive Delta variant are prompting some firms to rethink their plans. read more JPMorgan has brought back employees in the United States to the office on a rotational basis from July. The bank did not indicate any changes to work from office plans in the memo.