Health-care companies fell as investors retreated from growth sectors, rotating into sectors that had not participated in the summer rally, such as financial and industrial companies.

A small Russian study of a Covid-19 vaccine showed promise with immune reactions, according to a paper published in prestigious British medical publication The Lancet.

Shares of Covid vaccine developer Moderna fell sharply after its chief executive said it was slowing down enrollment in the late-stage clinical trial vaccine to ensure diversity of the study's participants. 



  Write to Rob Curran at rob.curran@dowjones.com