Florida is rapidly approaching the peak of new infections of the delta wave, when the highest single-day counts could come, according to two models created by researchers at Florida universities.
One model created by University of South Florida researchers predicts the state will hit the most daily infections by Tuesday (Aug. 24), bringing about 23,000 that day, said Dr. Edwin Michael. Because the delta variant has infected so many unvaccinated people, and more than 66% of Floridians have been immunized, he said the state will likely hit herd immunity in early September.
If immunity gained from infection proves to be long-lasting — though research has indicated it offers shorter protection than that of the vaccine — and if vaccines hold, Michael said the pandemic could end by early next year.
“If immunity is long term, this will be the last significant wave,” he said, noting “flare-ups” could still occur. “There’s a lot of caveats to this.”
The Centers for Disease Control and Prevention says people who have been infected and recovered from COVID-19 should still get vaccinated.
“If you have had COVID-19 before, please still get vaccinated,” said Dr. Rochelle Walensky, the CDC director, this month, following the findings of a study showing unvaccinated people are two times more likely to be reinfected.
A University of Florida model predicts a similar timeline, projecting a peak to come at the end of last week or sometime next week, said Dr. Ira Longini, a biostatistician who helped develop it. The model, updated Aug. 14, predicts a more severe summit at about 33,000 cases in a single day, or 150 cases per 100,000 residents, according to a report published by the school.
But hospitalizations and deaths spike days and weeks after symptoms arise, Florida will be feeling the effects of the delta variant for weeks and months to come, Longini said.
“I would think through a lot of September we’re going to see a lot of hospitalizations and deaths and strain on the system,” Longini said. “By October, things should be back down to a more endemic level like we’re seeing in May and June.”
In further evidence that the peak is near, new infections in Orange County are growing at a slower rate week over week than they were earlier in August, said Dr. Raul Pino, the state’s top health official in the county. New infections were essentially flat last week statewide compared with the week prior, coming with about 150,000, or about 1,300 fewer. In Orange County, there were about 8,900 fewer infections compared with 9,600 the week prior and the positivity rate went from 18.4% to 18.3%.
“If you have had COVID-19 before, please still get vaccinated."
The county’s positivity rate has also held steady at 20%, which while sky-high, appears to have stopped climbing. Local hospitals also said new inpatient growth has slowed, even as more people are hospitalized locally and statewide than ever before.
The USF model predicts the high mark for hospitalizations will come about Sept. 8, where about 19,000 hospital beds will be needed for COVID-19 patients.
By Friday, 16,849 people were hospitalized with the virus, according to the Florida Hospital Association.
Projecting the peak daily death toll is tricky, Michael said, because hospitals have gotten better over the past 17 months at treating critically ill patients. And the availability of monoclonal antibody treatments — pushed by both President Joe Biden’s administration and Gov. Ron DeSantis — have also been proven in clinical trials to reduce hospitalizations in the virus fight.
But the model shows Sept. 14 as the projected high for daily deaths at about 330, Michael said.
The USF tool focuses on county-level data, including health information, cell-phone tracking data to assess mobility, Google search trends on topics like face masks and social distancing, as well as vaccination rates to track the pandemic.
So, like a weather forecast, the results can vary, Michael said. For example, over the past month, as businesses began requiring facial coverings and more people began wearing masks as cases exploded in Florida, the model has seen its projected peak become less severe.
Last month, the model predicted Florida would see a peak with daily case counts around four times higher than January’s highs and threaten to overwhelm hospitals. But with more measures instituted and vaccination rates climbing, now the projected high is about 1.5 times the January peak, and coming weeks sooner.
The University of Florida model accounts for people going to work and school and movement levels based on cell-phone data, as well as vaccination rates and virus transmission, Longini said.
“We watched what happened in India with the delta variant and other places, it’s exactly what’s happening in Florida right now,” he said.
He said because most of the world isn’t vaccinated, there’s still a high potential for the virus to mutate and form variants more infectious than delta and that are better at evading immune systems. Eventually, they could make it to the United States, and inevitably, Florida.
“If Florida doesn’t change its policies we could just see wave after wave,” he said.
Michael said the state still faces dangers in the virus fight as long as herd immunity isn’t reached.
“If Florida doesn't change its policies we could just see wave after wave."
Michael said the bar has been raised to reach herd immunity, which is when enough people have protection against disease to prevent its spread because variants have become more infectious. Now, to reach that level, he said 90% of the population needs immunity.
“In the next four weeks, the strategy would be to try to get the most people vaccinated [as] possible. We’re very close to herd immunity if no other mutant arrives and if immunity is lasting,” he said, “it could be the endgame. But we need help.”
About the Author
