As COVID-19 cases continue to creep up in Central Florida, additional evidence has emerged that previously infected or vaccinated people may have less protection against new omicron variants than other types of the virus.
The omicron variant of COVID-19, first detected in the U.S. in November, is one of many mutations that have emerged as the COVID-19 virus attempts to spread by replicating itself.
Omicron, seemingly better able to infect previously infected or vaccinated people than past variants, launched Florida cases to record highs last winter.
From omicron, a more infectious strain emerged: BA.2. After BA.2, strains seemingly even more contagious emerged: BA.2.12.1, BA.4 and BA.5.
About three weeks ago, Orange County, Altamonte Springs and Casselberry began testing wastewater for traces of BA.2.12.1, the most common variant in the U.S. right now, followed by BA.5 then BA.4, according to the Centers for Disease Control and Prevention.
As suspected, they found BA.2.12.1 in their sewer service areas, which stretch throughout Orange and Seminole counties.
“Orange County can confirm that BA.2.12.1 is present in our community’s wastewater system, along with the original Omicron and BA.2 subvariant,” Orange County Utilities spokesperson Sarah Lux said in an email.
COVID-19 is detected in sewage by analyzing wastewater for SARS-CoV-2 viral genomes — fragments of the virus found in infected or recently infected people’s stool.
In Monday’s sample, 52.8% of the genomes in the Altamonte Springs sewer service area and 42.9% of the genomes in Casselberry’s sewer service area were BA.2.12.1, Altamonte Springs City Manager Frank Martz said.
The high prevalence of these omicron subvariants suggests Central Florida residents shouldn’t view vaccination or prior infection as a guarantee they won’t get infected.
The New England Journal of Medicine published a report on Wednesday that finds the BA.2.12.1, BA.4 and BA.5 subvariants “substantially escape” antibodies that are supposed to protect people who were vaccinated or previously infected from getting the virus again. This echoes the conclusion of a study draft from scientists at Columbia University’s Aaron Diamond AIDS Research Center.
The researchers behind Wednesday’s study, from Harvard Medical School’s Beth Israel Deaconess Medical Center, found both vaccinated people and people who were infected with earlier versions of omicron produced lower levels of antibodies when exposed to BA.2.12.1, BA.4 and BA.5 than when exposed to other versions of omicron.
Even though vaccines are less likely to protect against infection, they will likely still hold up against severe disease, Dr. Dan Barouch, an author of the paper and director of the Center for Virology and Vaccine Research at Beth Israel, told CNN.
“Our data suggest that these new Omicron subvariants will likely be able to lead to surges of infections in populations with high levels of vaccine immunity as well as natural BA1 and BA2 immunity,” Barouch wrote. “However, it is likely that vaccine immunity will still provide substantial protection against severe disease with BA4 and BA5.”
Next week, the lab serving Orange County, Altamonte Springs, and Casselberry will begin analyzing wastewater across Central Florida with a newly developed test for BA.4 and BA.5 variants, Lux and Martz said.
Orange, Seminole, Lake, and Osceola counties currently have a high COVID-19 community level along with the majority of Florida, according to the CDC’s website.
By the CDC’s definition, this means hospitalization rates are high enough that the current COVID-19 wave could threaten resources in most Central Florida counties if efforts to curb the spread aren’t taken.
The CDC recommends mask-wearing in any county with high community levels.
Orange’s rolling average test positivity rate is at 25.2% as of Thursday. Osceola is at 24.5%, Lake at 26.9%, and Seminole at 30.9% as of last Friday, though positivity rates are based on only a fraction of COVID-19 tests due to the rise of at-home testing.
ccatherman@orlandosentinel.com; @CECatherman on Twitter
