Doctor says your mask won't help you against coronavirus. Here's why

A new case of coronavirus in California “marks a turning point,” according to the state’s public health director, because the patient has no related travel history and no known exposure to coronavirus. Dr. Alok Patel joins Anderson Cooper to answer your coronavirus questions live. Watch “Full Circle” weeknights at 5 p.m. ET.

02:01 - Source: CNN
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CASALPUSTERLENGO, ITALY - FEBRUARY 23: A man wearinig a respiratory mask and gloves is pictured on February 23, 2020 in Casalpusterlengo, south-west Milan, Italy. Casalpusterlengo is one of the ten small towns placed under lockdown earlier this morning as a second death from coronavirus sparked fears throughout the Lombardy region. (Photo by Emanuele Cremaschi/Getty Images)
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Doctor says your mask won't help you against coronavirus. Here's why
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