by Paul Govern. Enrollment in the Vanderbilt Health patient portal, My Health at Vanderbilt (MHAV), has surged in recent months. "Before COVID, we were enrolling about 3,000 new users per week. After COVID, it spiked to about 9,000 per week for a bit, then stabilized to around 5,000 per week," said Trent Rosenbloom, MD, MPH, director of MHAV..