Is the BA.5 COVID-19 subvariant super contagious?

July 19, 2022
The BA.5 COVID-19 variant is spreading widely. Here, a woman in a mask sees her doctor. Photo: Getty Images.
The BA.5 COVID-19 subvariant is highly infectious. Learn how to stay safe and what to do if you get sick. Photo: Getty Images.

It seems like everyone is dealing with COVID-19 this summer — even the president of the United States.

The White House announced that President Joe Biden tested positive for the virus that causes COVID-19 on July 21. If you’re sick too, or you have friends and relatives who’ve struggled this summer, you can blame a highly infectious omicron subvariant known as BA.5.

To help you understand what is going on with COVID-19 now and what the BA.5 subvariant is, we consulted with Dr. Michelle Barron, UCHealth’s senior medical director of infection prevention and control and a professor at the University of Colorado School of Medicine on the Anschutz Medical Campus.

What is BA.5?

BA.5 is the newest subvariant to be causing COVID-19 infections. According to data from the U.S. Centers for Disease Control and Prevention (CDC), BA.5 is now causing nearly 70% of COVID-19 infections in the U.S.

BA.5 is a subvariant of omicron, the variant that has out-competed other versions of the SARS-CoV-2 virus. That’s the virus that causes COVID-19. The original virus has evolved over time, which is typical of viruses. Omicron became the dominant variant in the beginning of 2022 and BA.5 has taken over as the dominant subvariant this summer.

Why am I hearing so much about BA.5 now?

BA.5 is a hot topic this summer because it’s incredibly infectious, much more so that the original version of the SARS-CoV-2 virus.

“BA.5 is having its moment because it has perfected how to transmit the virus from person to person,” Barron said. “The virus wants to survive. How does it survive? It keeps perpetuating itself.”

In order to spread, the BA.5 subvariant has figured out how to evade vaccines and infect people who have recovered from relatively recent cases of COVID-19.

Researchers are debating exactly how much more infectious BA.5 is. Scientists estimated that people who became infected with the original SARS-CoV-2 virus each spread it to about 2 or 3 other people. The delta variant — which dominated in late 2021 — was even more infectious. It had what scientists call an R-naught value of about 7, meaning each person who was infected with the virus could spread it to about 7 people. The omicron variants, including BA.5, are even more infectious than the delta variants. Scientists are still debating exactly how much more. One Australian statistician theorized that each person who got BA.5 could spread it to 18 others, which would put BA.5 on par with the infectiousness of measles. Other researchers are challenging that notion, and time will tell exactly how contagious BA.5 proves to be. Suffice it to say that BA.5 is easy to get.

Barron said that’s no surprise. Viruses adapt so they can spread better and survive longer.

You could think of BA.5 as a sneaky, speedy racehorse. It’s sneaky because it can bypass vaccine protection and antibodies from previous infections. And it’s fast at spreading.

BA.5 has borrowed survival skills from delta and other omicron variants that helped it spring to the front of the pack.

“It’s like a thoroughbred. When people breed horses, they find different characteristics to make the horse next level,” Barron said.

That’s how this particular variant is. It’s good at beating the competition.

I hear that BA.5 COVID-19 infections are spreading widely. Is that true?

Yes, that’s definitely true, Barron said.

But it’s hard to tell exactly how bad this current wave of COVID-19 infections is compared with earlier spikes. That’s because many people are not getting tested. Or they’re doing tests at home and are not reporting positive results to state and county health departments.

“The positivity rates are not truly representative,” Barron said. “The number of people who are being tested is lower overall. And the people who are getting tested are typically symptomatic (rather than large swaths of the population getting tested).”

Official positivity rates are quite high now and aren’t conveying the full picture.

“We’re missing all the home test results,” Barron said. “A lot of people have COVID-19 now.”

Does BA.5 make people sicker than previous COVID-19 variants or subvariants?

No. Not so far. Many, many people are getting sick. But so far, hospitalizations have not risen dramatically, Barron said.

“BA.5 doesn’t kill people fast. It’s doing what it’s supposed to do to survive: transmitting rapidly to as many people as possible and making them sick without killing most of them. If you kill (your host) too quickly, then you can’t keep spreading,” Barron said.

What should I do if I get BA.5?

First, if you test positive at home or elsewhere, you must assume you have COVID-19, and you should isolate to reduce the likelihood of spreading your illness to others.

If you have any underlying conditions, call your doctor right away. There are newer treatments that can help you fight your infection. It’s important to get these treatments early in the course of the illness, so call for help quickly.

Some people are at high risk for getting very sick from COVID-19, Barron said.

“If you are 60 or older and have underlying medical problems like diabetes, cancer, asthma or you’re very overweight, then you should get additional treatments,” Barron said.

Doctors can prescribe medications like paxlovid or remdesivir. Learn how to get these treatments.

How do you know if you need to see your doctor in person or you need emergency care at a hospital?

By all means, if you are not feeling well, seek help. In the early days of the pandemic in 2020, many people were afraid to go to the doctor’s office or to seek care in hospitals.

These days, doctors have many treatment options. To prevent severe illness or death, it’s critical to ask for help if you are severely ill or you were improving from a COVID-19 infection, but have declined and gotten sicker.

“The course of these infections is that you should progressively be getting better over three to five days. Your fever should break,” Barron said.

“If your fever is persisting or you are unable to eat or drink, or you’re feeling weak or you have any kind of breathing problems, you need to be seen,’’ Barron said.

She has known some people who appeared to be recovering from a COVID-19 infection, but declined after about 10 days. Especially with older people during the summer, dehydration can be dangerous. If you are not feeling well, seek help immediately.

“It’s so hot right now. If you’re sick, often you’re not able to eat or drink well. People don’t think about the dehydration piece,” Barron said.

Her message is clear: Seek help if you need it.

“We have good treatments now. We’ve come a long way. There are risks of serious complications from COVID-19, like blood clots and cardiac events. If you are not feeling right, make sure to be seen by a doctor,” Barron said.

Is the BA.5 COVID-19 subvariant going to continue dominating throughout the summer and fall?

It’s impossible to know exactly how the COVID-19 variants and subvariants will continue to evolve.

Borrowing the horseracing analogy again, Barron said new versions of viruses often seem to spring from nowhere.

“At a horse race, you have your contenders, and you think you know how they’re going to do. You get the odds for each horse. But then, out of left field, some horse flies through and beats every other horse. You didn’t expect it and you couldn’t possibly predict that horse would win because that’s how horse racing works,” Barron said.

The same is true with viruses. It’s typical for dark horse variants to emerge and take over.

Researchers can guess how the SARS-CoV-2 viruses will evolve — or create the odds for new virus strains — but they can’t guarantee that those predictions will be accurate.

Do the current vaccines help fight BA.5?

Yes. While the current vaccine versions are not perfect at preventing infections, people who are vaccinated and received boosters seem to be getting milder cases. The aim of the vaccines is to prevent death and serious illness that requires hospitalization.

Learn all about omicron-specific booster shots that are coming this fall.

Is BA.5 causing dangerous spikes in hospitalizations for COVID-19?

Not so far. While BA.5 is extremely good at spreading, like earlier omicron subvariants including BA.2 and BA.4, BA.5 does not appear to be causing a more severe form of COVID-19.

“The good news is that even with high transmission in the community, we are not seeing new surges in hospitalizations. So that’s really good,” Barron said.

Still, context is important.

Hospitalizations in Colorado have been at a plateau throughout the spring and early summer.

“We never really went down,” Barron said.

I hear BA.5 causes mild to moderate COVID-19 infections for most people. Is that true? And what does mild to moderate mean anyway?

It is true that BA.5 is causing mild to moderate infections in most people. But mild to moderate can still feel pretty lousy. Barron is hearing from many people who feel lousy and are not recovering quickly.

“Epidemiologically, when we talk about mild or moderate cases, it means you did not die or end up in the hospital. But that doesn’t mean that you were not impacted by it. And of course, there’s variability. I’ve known many people who have been pretty sick. They’re tired and in bed,” Barron said. “It’s not the end of the world because most people are not going to die from BA.5. But, it’s not like your nose runs for a day and your fine.

“We’re seeing people who feel like they have the flu and are knocked out for a few days, some even longer,” Barron said.

What if I got COVID-19 recently? Can I get it again?

Yes. Over time, experts have learned that people can get COVID-19 more than once. The immunities from infections and antibodies from vaccines seem to wear off over time.

What are the typical symptoms of a BA.5 infection?

The symptoms with a BA.5 infection are similar to symptoms from previous versions of COVID-19.

BA.5 symptoms include: fever, chills, coughing, runny nose, sore throat, exhaustion, severe headache, muscle aches, gastrointestinal problems for some people, and in some case, loss of taste and smell.

Are rebound symptoms typical of BA.5 COVID-19 infections?

Yes. Some people are experiencing symptoms that linger or recur.

Barron said these up-and-down cycles are typical of respiratory infections.

“If you think about being sick over your lifetime, you’ve had some pretty bad colds. You were out for two, three or four days. Then, sometimes it can take a long time to stop coughing or to sleep well again,” Barron said. “Respiratory viruses can do this. You look at people who have had the flu, and sometimes, a month later, they’re still feeling lousy.”

Infections seem to be worse if the infection travels from the upper respiratory tract (the nose, mouth and throat) into the lower respiratory tract (the lungs).

“When you get lower-tract diseases, which affect your lungs, your body has a stronger immune response. Your body responds like it’s been hit by a nuclear bomb and tries to recover. Sometimes, that takes time,” Barron said.

What can I do to prevent BA.5 or other COVID-19 subvariants from infecting me?

Anyone who isn’t vaccinated should get vaccinated. The U.S. Food and Drug Administration has approved a more traditional type of vaccine called Novavax.  The previous Moderna and Pfizer vaccines are what’s known as mRNA vaccines. If anyone was concerned about getting an mRNA vaccine, they can now get Novavax.

If you haven’t gotten your booster doses, get them now. New omicron-specific boosters are coming this fall, but Barron is advising people not to wait for the new version.

“The boosters are available and worth getting. Some people are saying, ‘I’m just going to wait.’ Don’t do this. That’s like swimming out to sea and saying, ‘I’m going to see if I might drown’ before putting on a life jacket,” Barron said.

“We’re in the middle of the ocean now, and it’s filled with COVID-19. Your chances of being exposed right now are quite high. Get your booster and protect yourself with your life jacket now,” she said.

Finally, masks work.

While airports and other crowded indoor settings are full of people who are no longer wearing masks, you can choose to do what Barron does and mask up.

“Whatever your feelings are about masks, they work. So, you can decide whether or not to wear them, but they work,” Barron said. “And, they are required in health care settings.”

About the author

Katie Kerwin McCrimmon is a proud Colorado native. She attended Colorado College, thanks to a merit scholarship from the Boettcher Foundation, and worked as a park ranger in Rocky Mountain National Park during summer breaks from college. She is also a storyteller. She loves getting to know UCHealth patients and providers and sharing their inspiring stories.

Katie spent years working as a journalist at the Rocky Mountain News and was a finalist with a team of reporters for the Pulitzer Prize for their coverage of a deadly wildfire in Glenwood Springs in 1994. Katie was the first reporter in the U.S. to track down and interview survivors of the tragic blaze, which left 14 firefighters dead.

She covered an array of beats over the years, including the environment, politics, education and criminal justice. She also loved covering stories in Congress and at the U.S. Supreme Court during a stint as the Rocky’s reporter in Washington, D.C.

Katie then worked as a reporter for an online health news site before joining the UCHealth team in 2017.

Katie and her husband Cyrus, a Pulitzer Prize-winning photographer, have three children. The family loves traveling together anywhere from Glacier National Park to Cuba.