The latest mutation of the coronavirus is becoming dominant in South Florida, but immunity keeps the worst symptoms at bay

A more contagious subvariant of the coronavirus that causes COVID-19 is spreading rapidly in South Florida and becoming dominant in the country.

In the week ending January 21, 2023, this omicron subvariant, called XBB.1.5, accounted for 39% of cases in a region of the US that includes Florida, Georgia, Mississippi, North Carolina, and the United States. South and Tennessee, according to the US Centers for Disease Control and Prevention.

The spike protein of this subvariant has a mutation, or change in the spike, called F486P, which allows it to more easily attach to human cells and enter, spreading the virus.

“That’s why we’re seeing it more and more,” said Dr. Aileen Marty, an infectious disease expert at Florida International University.

This subvariant of the SARS-CoV-2 virus, which causes COVID-19, is not weaker than others. But people are not experiencing terrible severity in side effects due to immunity in our population.

“Omicron is a really bad virus, but we’ve built up immunity in our population because we’ve had a very high infection rate,” Marty said. “People with hybrid immunity have much better immunity than people who just have infection and have never had the vaccine. That’s not a good option, and hybrid immunity also turns out to be better than just the vaccine.”

Marty said that the oral antiviral called Paxlovid is quite effective in keeping patients out of hospital, while currently available monoclonal antibodies are not effective against most circulating variants, he added. If the US did more genetic sequencing of coronavirus variants, doctors would know what infection their patients have and thus better know what to prescribe.

The experience of adults with this variant seems similar among children. Nicklaus Children’s Hospital in Miami is not seeing an increase in the number of children being admitted with severe cases of COVID-19, said Dr. Marcos Mestre, vice president and chief medical officer. Some children “have been infected, they’ve had vaccinations, they’ve had some degree of boost, so we haven’t really seen as much in terms of severity as we were seeing with other variants in the past,” Mestre said.

But the subvariant is contagious. According to the Centers for Disease Control and Prevention Data Tracker, Miami-Dade County has a high level of SARS-CoV-2 transmission, while Broward and Palm Beach counties have a medium level.

Dr. Mestre recommends that people continue to wash their hands frequently. If you have a cough or fever, or if your child has these symptoms, try to stay home from work or school.

To get tested, if you have medical care, check to see if a testing site is in the network by contacting the insurer or asking at your doctor’s office.

The Florida Department of Health in Monroe County lists testing sites with specific guidelines for who may qualify for a free test; check with the site or your insurer before getting tested.

The uninsured and insured do not pay for testing at Nomi Health sites in Miami-Dade, due to a partnership between the company and the county.

Broward County lists three sites operated by the local Florida Department of Health that offer free PCR testing.

Palm Beach County has a list of sites; some offer tests at no cost.