Top coronavirus modeler Murray says masks are only 50% effective at stopping transmission

One of the most prominent experts associated with the U.S.'s coronavirus mitigation efforts says wearing a mask offers only about 50% protection from getting infected by coronavirus, amid some public health officials contending that the routine wearing of a face-covering is the next, necessary tactic toward slowing the spread of the virus. 

Christopher Murray, a professor at the University of Washington and director of its Institute for Health Metrics and Evaluation, has been at the forefront of the American outbreak since March, when White House officials began citing his pandemic model as partial justification for ongoing state-level lockdowns of much of the United States economy. 

That model has faced criticism for its repeated overestimation of COVID-19 hospitalization rates, though health authorities have continued to cite it as the pandemic continues. 

On Wednesday, CNN, in a story about the growing usage of face coverings in the United States, quoted Murray as saying face masks are effective only by about half at reducing transmission of the disease. 

"We now have really clear evidence that wearing masks works — it's probably a 50% protection against transmission," Murray told CNN, adding that "what happens in the next month or two is very much in the hands of how people respond."

That estimate tracks largely with one made by retired University of Chicago professor Lisa Brosseau, who told Just the News this month that cloth masks "stop about 50 percent of particles."

Brosseau, however, was less optimistic than Murray about their ultimate effectiveness. 

"If it takes you two or three minutes to get an infectious dose, the mask may move the infection time up a little bit longer," she said. Brosseau also argued that physical distancing was the more effective solution for pandemic mitigation. 

States such as New York and Virginia have made mask-wearing mandatory in many public places and establishments. In Los Angeles, meanwhile, residents are required to wear masks whenever they go outside.