Vanderbilt study says spread of COVID-19 is slowing, researchers call progress ‘fragile’

NASHVILLE, Tenn. (WKRN) — New research from Vanderbilt University says Tennessee and specifically, Nashville, have effectively slowed the spread of COVID-19.

“What we’re seeing is real success and Tennesseans should feel good about that, we’ve worked hard on our social distancing,” said Dr. Melissa McPheeters, research professor for Vanderbilt’s Health Policy and Biomedical Informatics. McPheeters also serves as co-director for the Center for Improving the Public’s Health through Informatics.

Despite the improving numbers, McPheeters said the progress is fragile.

She said, “One of things we know about the transmissibility is that it can rebound really fast.”

The study largely centers on the novel coronavirus’ transmission rate. The transmission rate measures the number of people that contract COVID19 from one infected person.

Vanderbilt’s latest report, released on Thursday, shows a decline in the virus’ spread with a transmission rate of around 1.0. Researchers believe the transmission rate was 1.4 on April 6, and possibly as high as 5.5 when the outbreak first began in Tennessee.

The study also compares regional transmission rates, showing that the Knox East region, followed by the Tennessee Highland Rim (which includes the Metropolitan Nashville area) have slowed the spread of COVID-19.

Of the regional data, McPheeters said, “Certainly our Nashville area started some of the social distancing activities a little bit earlier than other places in the state, so they dropped down a little bit faster. I want to caution people not to put too much into comparing across the regions because when we look at those color bands in our report, some of them are very big, very wide. That means there is a lot of potential play into where the estimate actually is.”

According to the study, the research team has been using countries with similar transmission numbers like Singapore and Sweden, to make comparisons and keep realities in check.

McPheeters said of Singapore, “In one week they went from a transmission rate of about 1.2, which is a little higher than where we are right now…but close to where we were last week…all the way up to 2.5 in eight days.”

She said to slow the virus’ spread, a transmission rate below 1.0 needs to be sustained.

“That way we can manage it. Our healthcare system can manage the number of sick people we’re dealing with and that we’re protecting our vulnerable populations.” she added.