OU's Chief COVID Officer Dr. Dale Bratzler discussed COVID-19 vaccine and treatment trials, physical distancing, mask efficacy and more in a Tuesday town hall.
The July 14 presentation also discussed mask types, risk factors and comorbidities, the iceberg effect, and the Oklahoma COVID-19 Alert System. The Oklahoma State Department of Health reported 699 new COVID-19 cases Friday.
According to the presentation obtained by The Daily, physical distancing, face masks and eye protection can prevent person-to-person transmission of COVID-19. In the case of physical distancing, there is an 82 percent relative reduction of spread and in the case of mask-wearing, an 85 percent relative reduction.
Bratzler said different mask fabrics can alter the efficacy of virus transmission. In a mask made with a bandana, the droplets traveled 3 feet and 7 inches. With a folded cotton handkerchief, droplets traveled 15 inches. With a stitch quilting cotton mask, droplets traveled 2.5 inches. With a cone-style mask, droplets traveled 8 inches.
The Centers for Disease Control and Prevention currently suggest keeping a physical distance of at least 6 feet, but respiratory droplets have been recorded to travel more than 8 feet without the use of a mask, according to the presentation.
The virus typically spreads through close person-to-person contact via respiratory droplets from coughing, sneezing and speaking. The virus may also spread through airborne transmission — when tiny droplets of the virus remain in the air even after an infected person has left the area — or from touching a contaminated surface, and then touching your mouth, nose or eyes, according to the presentation.
Looking forward, Bratzler cited three clinical trials for treatments with promising results — Dexamethasone, Remdesivir and Tocilizumab. According to the presentation, case fatalities are decreasing and at least two vaccinations have entered Phase III trials — the phase where thousands of people are administered a vaccine to test for safety and efficacy, according to the CDC.
Bratzler also discussed the Oklahoma COVID-19 Alert System, which was developed by the OSDH and uses a color-coded system to identify the risk levels in each Oklahoma county of contracting the virus. The four-step system ranges from “new normal” to “low” to “moderate” to “high” risk.
As of July 16, Norman and the rest of Cleveland Country are classified in the “low” risk category. Oklahoma County is in the “moderate” risk category.
The personal risk factors for severe disease are outlined in the presentation by comorbidities in deceased patients. The most common conditions are chronic heart or circulatory disease, diabetes, chronic renal failure, chronic lung failure, chronic liver failure or having at least one other chronic condition.
The presentation also discussed the presence of the “iceberg effect.” This effect suggests the number of undiagnosed cases is likely higher than anticipated and thus, the visible number of cases is just the “tip” of the iceberg. The invisible cases are likely asymptomatic carriers who spread the virus without ever knowing they contracted it.
“You must assume that any person you encounter could be infected,” Bratzler’s presentation read.
