The highly contagious omicron variant set pandemic infection records in Florida and the U.S. and is still spreading across many states and the rest of the world.
But coming up fast behind it is a subvariant that early studies suggest is even more infectious, may cause more breakthrough infections in the vaccinated — and now it’s in Florida.
The COVID-19 subvariant is designated as BA.2 but is better known by its nickname “stealth” omicron. It was first detected in Denmark in December and already has overtaken the original omicron strain to become the dominant variant in that country. It has been identified in at least 57 countries and 29 U.S. states as of Monday, according to GISAID, a public database used by scientists to track the spread of infectious diseases. Data from around the globe shows the subvariant steadily outcompeting omicron.
Now two cases of the BA.2 subvariant have been identified in Florida in a seven-day span, according to GISAID.
A 69-year-old female tested positive for BA.2 from a nasal swab sample taken on Jan. 11. The sample was submitted to a Centers for Disease Control and Prevention testing lab and reported as positive on Jan. 25.
The other case is a 32-year-old man who was tested on Jan. 16, and that positive test result was reported Tuesday. No other details about either case were available, including what counties they live in.
The Florida Department of Health is aware that the subvariant has been detected in the state, said department spokesperson Jeremy Redfern.
“You would need to contact the CDC for further information,” Redfern said in a Tuesday email to the Tampa Bay Times.
The BA.2 subvariant may be more widespread than those early results indicate. Florida only sequences and shares 2.3 percent of samples that test positive for COVID-19 with GISAID.
Scientists don’t know yet whether it will produce more severe symptoms in those infected. The World Health Organization’s COVID Response Team said in a briefing Tuesday that it does not seem to be any more severe than the original omicron strain, according to a report from Reuters.
There is positive evidence that suggests the subvariant is similar enough to omicron that vaccines should still be able to protect against severe COVID-19 symptoms, said Seetha Lakshmi, medical director of Tampa General Hospital’s Global Emerging Diseases Institute and an assistant professor at the University of South Florida’s division of infectious disease.
However, the subvariant could delay a return to something approaching “normal,” which experts had predicted could come by early March based on the falling number of omicron cases. Stealth omicron may not produce another infection wave, Lakshmi said, but it could prolong the current wave and maintain high levels of COVID-19 transmission for several weeks.
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“The expectation is it won’t give us as steep of a decrease in terms of caseloads,” she said. But whether it will send more people in hospitals “that’s something we will have to see.” she said.
The BA.2 subvariant, is considered a cousin of omicron, or BA.1, which has torn through Florida and as of last week was still infecting more than 28,000 residents a day, according to state data.
BA.2 does show up in standard COVID-19 tests, but earned its “stealth” nickname because it lacks one particular mutation that allowed researchers to easily distinguish omicron from previous variants using a simple PCR test. Without that key mutation, the BA.2 variant is indistinguishable from previous variants without more complicated lab-based tests, known as genomic sequencing.
A recent study out of Denmark indicates the new variant may be about 34 percent more infectious than the original omicron strain, on average. The risk of spreading the new variant is highest among the unvaccinated, but even vaccinated and boosted individuals have an increased risk of transmission. The study has not been peer reviewed.
BA.2 has a significant number of distinct mutations. Those differences mean that people who have been infected with BA.1 may still be at risk of getting infected with BA.2, said Anders Fomsgaard, chief physician at the Statens Serum Institut in Denmark, during a Jan. 21 appearance on Danish television.
That means a prior omicron infection many not provide as much protection from reinfection as hoped. That’s partially because the body mounts a weaker immune response to the relatively milder omicron infection, according to a study released last week.
Researchers found that antibodies produced after an omicron infection don’t do well at recognizing other variants, suggesting that it won’t offer much protection against a significantly different strain of COVID-19. That paper has not been peer-reviewed.
Tampa General conducts regular genomic sequencing of viruses to keep tabs on what diseases are spreading around the community. But some countries don’t have the resources to conduct as much genomic sequencing as richer countries, said Lakshmi. That makes it tougher for the health authorities in those nations to track what variants are spreading. And every time COVID-19 spreads and reproduces around the world, she said, the risk is more variants will emerge.
“The real challenge is a global response,” she said. “We’re globally connected but we’re not when it comes to a response to COVID.”
Correction: A Danish study indicates the BA.2 subvariant may be about 34 percent more infectious than the original omicron strain. An earlier version of this report cited an incorrect figure.
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How to get tested
Tampa Bay: The Times can help you find the free, public COVID-19 testing sites in Citrus, Hernando, Hillsborough, Manatee, Pasco, Pinellas, Polk and Sarasota counties.
Florida: The Department of Health has a website that lists testing sites in the state. Some information may be out of date.
The U.S.: The Department of Health and Human Services has a website that can help you find a testing site.
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How to get vaccinated
The COVID-19 vaccine for ages 5 and up and booster shots for eligible recipients are being administered at doctors’ offices, clinics, pharmacies, grocery stores and public vaccination sites. Many allow appointments to be booked online. Here’s how to find a site near you:
Find a site: Visit vaccines.gov to find vaccination sites in your ZIP code.
More help: Call the National COVID-19 Vaccination Assistance Hotline.
Phone: 800-232-0233. Help is available in English, Spanish and other languages.
Disability Information and Access Line: Call 888-677-1199 or email DIAL@n4a.org.
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More coronavirus coverage
OMICRON VARIANT: Omicron changed what we know about COVID. Here’s the latest on how the infectious COVID-19 variant affects masks, vaccines, boosters and quarantining.
KIDS AND VACCINES: Got questions about vaccinating your kid? Here are some answers.
BOOSTER SHOTS: Confused about which COVID booster to get? This guide will help.
BOOSTER QUESTIONS: Are there side effects? Why do I need it? Here’s the answers to your questions.
PROTECTING SENIORS: Here’s how seniors can stay safe from the virus.
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