- BA.5 is still classified as an omicron variant but has new mutations different from BA.1 and BA.2
- The first cases appeared in the Northeast, then began to spread to the South, the Midwest and the West
- Can you get BA.5 twice? Experts say it’s unlikely in the first month after infection
The BA.5 subvariant of omicron continues to dominate the summer surge of COVID-19 in the United States, accounting for nearly 80% of new cases, according to the Centers for Disease Control and Prevention’s Nowcast model.
In the most recent week, ending Wednesday, 29 states reported more cases than the previous week, a USA TODAY analysis of data from Johns Hopkins University shows this. Twenty states had more deaths than a week earlier.
Hospitals in 35 states reported more COVID-19 patients, while hospitals in 25 states had more patients in intensive care beds, according to health and human services data.
Here’s what you need to know about BA.5.
When did BA.5 start?
BA.5 was first detected in the United States in late April, experts said.
The subvariant was first seen in South Africa “but that doesn’t mean it arrived (in the United States) from South Africa,” said Johns epidemiologist David Dowdy. Hopkins Bloomberg School of Public Health. Researchers can’t know where it came from due to limited surveillance.
The first cases appeared in the Northeast, then began to spread over the past month in southern, midwestern and western states, Dowdy said.
“It’s been kind of a slow increase since that time,” he said. “It took about two months to get to the current state where we think BA.5 probably accounts for about two-thirds of all COVID cases now.”
What does BA.5 mean?
The World Health Organization uses the Greek alphabet as a classification system to simplify understanding and avoid stigmatizing countries where new strains of the SARS-CoV-2 virus that causes COVID-19 are first identified.
The WHO named the original variant B.1.1.529 after the 15th letter, omicron. In variants, the agency assigns numbers to its sublines.
“These represent the number and types of mutations within this particular variant,” said Dr. David Weber, professor of pediatric medicine and epidemiology at the University of North Carolina, Chapel Hill. “It’s a way of knowing what variant they’re dealing with.”
BA.5 is still classified as an omicron variant but has new mutations that distinguish it from other omicron subvariants, such as BA.1 and BA.2.
BA.5 variant symptoms in adults, children
Clinicians say many symptoms of BA.5 are similar to those seen in previous variants, including congestion, headache, cough and fever.
But children tend to have more gastrointestinal symptoms than adults, such as nausea, abdominal pain, vomiting and diarrhea, said Dr. Claire Bocchini, an infectious disease specialist at Texas Children’s Hospital.
She’s also seen more cases of croup in children, which the Mayo Clinic defines as an upper respiratory infection that obstructs breathing and causes a “barking” cough.
“This is definitely an infection to be aware of for parents of children, because while most children don’t require hospitalization, a few do,” Bocchini said.
How long does BA.5 last?
While some people experience no symptoms with BA.5, experts say those who do can expect to feel sick for a few days to a few weeks.
“It varies over a broad spectrum,” said Dr. Mobeen Rathore, a professor at the University of Florida College of Medicine and a member of the American Academy of Pediatrics’ infectious disease committee.
Bocchini said the normal course of illness is “one to two weeks of acute symptoms”, but those who are hospitalized may have the disease for much longer.
“We are very familiar with prolonged hospitalizations due to COVID complications,” she said.
Can you get BA.5 twice?
There is limited data to determine if a person can get BA.5 twice, but health experts say it’s unlikely to happen in the first month after infection.
“For the first two weeks, if you have a healthy immune system, you’ll probably be completely resistant to reinfection,” Dowdy said.
But that protection wanes over time, he said. If a person is exposed to COVID-19, it is possible to be reinfected with the same variant two to four months after infection.
Although possible, it is unlikely BA.5 will continue to circulate over the next few months as the population gains immunity to the subvariant. It is more likely that a new variant or sub-variant of omicron will emerge as the virus attempts to circumvent this immunity and infect as many people as possible.
It’s “a bit of a game of cat and mouse between the virus and our immune system,” Dowdy said. “If we don’t see another sub-variant emerge within the next two months, then yes, absolutely people will be re-infected with BA.5.”
What to do if you are infected with BA.5?
If you test positive for COVID-19 or start feeling ill with associated symptoms, CDC recommendations recommend staying home for at least five days and isolating yourself from other household members.
The agency also recommends wearing a properly fitted mask around other people at home.
If you don’t have a fever for 24 hours and symptoms improve after the five days, the CDC says you can end isolation but continue to take precautions for an additional five days. This includes wearing well-fitting masks around others inside and outside the home and avoiding travel.
How are BA.4 and BA.5 different? What are the other variants of COVID?
BA.4 and BA.5 share mutations with other omicron subvariants, such as BA.1 and BA.2, but contain additional mutations in the spike protein, according to the National Institute of Communicable Diseases, a national public health institute in South Africa.
The two subvariants are identical to each other in terms of spike protein mutations, the institute said, but differ in mutations outside the spike gene.
BA.5 evades immunity better than BA.4, Weber said. However, it is not thought to be more transmissible or to cause more severe disease.
Except for a few random cases here and there, Dowdy said there are probably no other circulating coronavirus variants outside of omicron and its sublines. Delta and the variants that preceded it are probably irrelevant.
“When we talk about COVID, we are now talking about omicron,” he said.
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
Coverage of patient health and safety at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
