No new COVID-19 cases after infected Missouri hairstylists worked with over 140. How?

Missouri health officials discovered no new coronavirus cases after two infected hairstylists served dozens of clients at a Great Clips hair salon. The Springfield-Greene County Health Department says the incubation period has passed after the hairstylists worked on 140 people at the location in Springfield. Six coworkers also were potentially exposed. “This is exciting news about the value of masking to prevent COVID-19,” Health Director Clay Goddard said in a news release. “We are studying more closely the details of these exposures, including what types of face coverings were worn and what other precautions were taken to lead to this encouraging result.”