A predictive model developed by two scientists at the University of Florida shows the latest COVID-19 wave in Florida still hasn’t peaked.
UF biostatistics professor Ira Longini, Ph.D., worked with Thomas Hladish, a UF biology research scientist, to develop a mathematical model that projects the number of reported COVID-19 cases in Florida through the end of 2021.
The resulting graph released Aug. 5 shows the Sunshine State is in the middle of a large outbreak of COVID-19 cases, and the state hasn’t quite hit its peak.
Based on the model, Florida’s COVID-19 cases will soon surpass the number of COVID-19 cases seen at any point during the pandemic.
Longini has been researching and analyzing COVID-19 data from the beginning of the virus outbreak. As a biostatistician, he studies and analyzes the control of infectious diseases, including vaccine trials and transmission studies. In his work, he uses mathematical models that consider various factors related to infectious diseases and project infections based on those factors.
Florida’s expected surge in COVID-19 cases, depicted in Longini’s projections, can primarily be attributed to the delta variant, which has higher transmissibility than the original COVID-19 variant and reduced levels of protection for vaccinated people or people who have already been infected with COVID-19, Longini said.
Given changing factors, Longini’s model can’t reliably predict any further out than December.
“We don’t know what the epidemic will look like in Florida after this wave we’re facing now. It could go back to the lower levels like it was in June and stay there, or even go to lower levels as we keep vaccinating people. Or it could go to a higher level. You just don’t know,” Longini explained.
One major factor that can affect the future of the pandemic is new variants. Longini mentioned he is monitoring the lambda (C. 37) variant, first detected in Peru in December 2020.
Longhini said the lambda variant could create another peak if it turns highly transmissible like the delta variant, but there isn’t enough information about lambda to make that determination yet. The morbid thing about studying infectious diseases is that more people have to be infected to gather enough data to draw inferences.
“They don’t know a whole lot about it yet, but it appears that it may be somewhat similar to the delta variant, but we don’t know yet. We need to study it,” Longini said.
According to GSAID, a database that tracks infectious diseases, lambda variant cases account for 1,062 COVID-19 cases in the U.S., just a fraction of the total COVID-19 cases. However, 147 of those cases were recorded in Florida.
The lambda variant has been classified as a “variant of interest” by the World Health Organization, a designation slightly lower than the delta’s “variant of concern” status.
Longini said if it turns out the lambda variant is highly transmissible, then another COVID-19 wave would be likely, but added, “it takes several months for these viruses to get going.”
And while there isn’t much that can be done about variants already created, Longini said stopping transmission can keep new variants from forming.
“Variants come about when there’s lots of transmission of the virus. It gives you opportunities for the variances. If you can get everybody in the world vaccinated, we wouldn’t see any variance anymore,” Longini explained.
Longini said there’s no magic vaccination percentage that will keep new variants from forming. Still, every additional vaccinated person helps, and wearing masks and social distancing during outbreaks will help keep viral transmission low.
He also acknowledged that while vaccinations are the best hope to keep new variants from forming, he doesn’t expect COVID-19 to ever fully go away.
“I think we’re probably facing a future kind of like with flu, where you probably have to get booster vaccinations every year, and when outbreaks get severe, we have to take measures to protect ourselves.”
Longhini works in the department of biostatistics in UF’s College of Public Health and Health Professions and UF’s College of Medicine.
Hladish is a research scientist in the biology department in UF’s College of Liberal Arts and Sciences.