AUSTIN (KXAN) — Roughly a week and a half after Austin-Travis County hit the average number of hospitalizations to qualify for Stage 2 risk-based guidelines, health leaders announced the area would stay in Stage 3 because of a metric that shows how prevalent community spread is in Travis County.

Health leaders said they were already considering community transmission rate in their decision to move to a new stage, but they haven’t introduced that metric to the public until now.

Before Friday, the metric largely used to determine which stage the area was in was the 7-day rolling average of hospital admissions, which is still on the dashboard and will still be factored into which stage we’re in, health leaders said.

So why now? Why weren’t community transmission levels introduced in, say, August?

In a joint Austin City Council, Travis County Commissioners meeting Tuesday morning, Dr. Desmar Walkes pointed to University of Texas COVID-19 Modeling Consortium projections that, according to Walkes, showed “if we move quickly into Stages 2 and 1 that we could possibly have surges in the November, December time frame.”

The plots below are from the UT Modeling Consortium and show projected COVID-19 hospital admissions in the Austin-Round Rock MSA through February. The first graphic shows projections under the current thresholds of the risk-based guidance system. Those projections showed the potential for a holiday spike in hospitalizations. The second graphic shows what happens if the threshold from moving from Stage 2 to Stage 1 (represented as blue and green respectively) is moved from a rolling 7-day average of 5 new hospital admissions to none.

  • risk-based projections
    Projected COVID-19 hospital admissions and ICU patient census assuming delta continues to spread with different guidelines (courtesy APH and UT)
  • risk-based projections
    Projected COVID-19 hospital admissions and ICU patient census assuming delta continues to spread with different guidelines (courtesy APH and UT)

Walkes said we could see a holiday spike for several reasons: vaccine efficacy waning six months after vaccination, an uptick in the number of social gatherings as we move towards the holidays and people relaxing and removing their masks.

“Their (UT Modeling Consortium’s) recommendations was to lower the threshold and the thought was that that would help in keeping the public more aware of masking,” Walkes said.

In an interview with the UT Modeling Consortium last week, KXAN learned that modelers were having conversations with APH about whether the current risk-based guidance system was going to be effective enough to stop that potential spike over the holidays.

“We’ve been working with the City of Austin to reevaluate the stage reopening strategies and the alert system overall,” Dr. Spencer Fox, associate director of the UT COVID-19 Modeling Consortium, told us Wednesday.

While models short-term show we will be in a plateau, or even see a bit of a dip in case numbers and hospitalizations, Walkes says UT models show that won’t last if Austin-Travis County isn’t diligent.

“I think what we’ve seen is that there’s significant immunity in our population however, there’s not enough immunity to prevent a large pandemic surge and so that’s our concern right now,” Fox said last week.

That concern was echoed in Tuesday’s COVID-19 briefing before policymakers as Walkes explained why their announcement Friday is happening now.

“Our goal is to avoid a surge,” Walkes said.