OU Chief COVID Officer Dr. Dale Bratzler discussed the delta variant, vaccine effectiveness and masking in school settings during a Thursday live stream.
Bratzler opened by revealing there were 1,581 new cases of COVID-19 in Oklahoma on July 22. He also explained that the CDC had ranked Oklahoma as number eight in most cases over the past seven days. The seven-day rolling average of COVID-19 cases in Oklahoma is 875 cases per day.
"Of all of the new cases of COVID-19 in the United States, about 83 percent can be attributed to the delta variant, and this number has gone up very rapidly," Bratzler said. "Part of the reason this particular virus spread so readily is that it attaches to human receptors very efficiently. So, if you're exposed to it, you're likely to get infected."
Bratzler noted a critical study that took place in China where researchers examined 169 people that were infected with the delta variant. The study compared the viral load from the delta variant to that of the original Wuhan variant and discovered that patients infected with the delta variant had 1,260 times more virus on average than people infected with the original viral strand.
"It grows very rapidly, and you have a lot of it," Bratzler said. "High viral load, the incubation time appears to be much shorter and allows for the infected to shed virus quicker, and then the virus is very efficient at attaching to human receptors. It's why we're seeing rapid growth in the number of delta variant cases."
Bratzler said fully vaccinated individuals are not likely to face hospitalization or death if they are infected with the delta variant. He cited an Israeli study that tested symptomatic and asymptomatic cases around outbreaks where researchers discovered the Pfizer vaccine was about 64 percent effective in preventing people from contracting breakthrough infections from the delta variant strain. However, those who are fully vaccinated were still capable of carrying and spreading the delta variant.
Last week, the American Academy of Pediatrics recommended everyone over the age of two in schools continue wearing a mask. Bratzler agreed with the suggestion as children under 12 cannot be vaccinated and vaccinated individuals are still capable of carrying the virus. He also spoke on the difficulty of enforcing masking policies only on the unvaccinated.
"The majority of people who are spreading the disease right now are young people who are not vaccinated," Bratzler said. "I just think we all have to be cognizant of the potential risks of a contagious virus in a population of kids who have very low vaccination rates."
Bratzler also briefly spoke on the lambda variant, which originated from Illinois.
"The current vaccines seem to give you protection against the lambda variant also," Bratzler said, "It probably isn't as contagious as delta. The key to all of the variants so far is to one, get vaccinated, and to two, wear a mask."
Bratzler emphasized a need for caution as delta variant outbreaks continue.
"The delta variant is going to be very local, and we're going to see some communities that are going to be impacted more than others," Bratzler said. "We have a lot of communities in Oklahoma that have very low rates of vaccination, and I think that we are going to continue to see clusters of outbreaks until these communities are vaccinated. Especially with the highly contagious delta variant."