Medical staff members treat a patient with COVID-19 last week in the intensive care unit of United Memorial Medical Center in Houston. Once a COVID-19 vaccine is available, experts say immunizing health workers first is the best way to curb deaths and stop transmission.

HOUSTON, TX – OCTOBER 31: Medical staff members treat a patient suffering from the coronavirus disease (COVID-19) in the COVID-19 intensive care unit (ICU) at the United Memorial Medical Center (UMMC) on October 31, 2020 in Houston, Texas. According to reports, Texas has reached over 916,000 cases, including over 18,000 deaths. (Photo by Go Nakamura/Getty Images)