Omicron BA.4 and BA.5 Symptoms: What To Know

Fact-checked on July 14, 2022, by Marley Hall, a writer and fact checker specializing in medical and health information.

The Omicron BA.4 and BA.5 strains of COVID-19 became the most common forms of the COVID-19 virus in the U.S. in 2022. While health officials didn't know as of September 2022 how they might affect the population, the good news is that symptoms don't seem to be that much different or worse than with Omicron or other types of COVID-19.

They do spread more quickly, however. Read on to learn what you need to know about the subvariants and how to stay healthy.

How Are the BA.4 and BA.5 Variants Different?

Every new COVID-19 variant raises questions about how the symptoms from a new type might affect our health, and the BA.4 and BA.5 Omicron subvariants are no different.

The quick spread of BA.4 and BA.5 sets them apart from other Omicron strains. Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky called them "more transmissible and more immune evading" than other Omicron variants in a 2022 White House press briefing.

In a September 2022 news release, the CDC also recommended updated booster shots that contain proteins targeting the variants for people ages 12 and older.

These two new subtypes made up the majority of COVID cases in 2022, according to the CDC data tracker page. BA.5 alone was responsible for 81% of cases in October 2022.

Here's what we know about what a BA.4 or BA.5 infection can look like and whether symptoms are any more severe than other COVID-19 strains.

What Are Symptoms of BA.4 and BA.5 Variants?

Like the other Omicron strains that have been dominant in the U.S. since December 2021, experts say BA.4 and BA.5 mainly cause cold-like symptoms and respiratory or breathing issues. The CDC reports that people's most common complaints when infected with Omicron include cough, runny nose, congestion, and fatigue.

"COVID tends to present similarly, and [it] may vary from person to person, but the most common stuff we're seeing are fevers, congestion, [and] sore throat," Katie Passaretti, MD, vice president and enterprise chief epidemiologist with Atrium Health, told Health. "Often the sore throat is the kind of [first] symptom, and then the rest kind of come on."

Once a classic sign of COVID-19 infection, loss of sense of smell or taste seems to be less common among patients getting sick with BA.4 and BA.5, Dr. Passaretti noted. But Passaretti has heard that people with BA.5 or Omicron may experience worse fevers and sore throats.

Other symptoms may show up with the newer strains, George Rutherford, MD, a professor of epidemiology at the University of California, San Francisco, told Health. Diarrhea, a common symptom for earlier variants, may turn up. So can other COVID-19 complaints like headache and muscle pain.

As of September 2022, BA.4 and BA.5 had been infecting large numbers of people for only a few months, making it difficult to confirm these slight differences in symptoms beyond what doctors were seeing.

It's also important to remember that COVID-19 affects everyone differently.

"[There are] adults who have had fevers of almost 40 degrees Centigrade [104 degrees Fahrenheit]," Dr. Rutherford told Health. "People said, 'It's the worst sore throat I've ever had.' Others say it's trivial."

Until more people have been sick with BA.4 and BA.5 longer, it will be hard to pinpoint the specifics of these symptoms, Dr. Rutherford said. But for the most part, most symptoms Rutherford was aware of were respiratory.

Less severe symptoms may also be causing the new strains to spread faster. The body's milder response to a BA.4 or BA.5 infection means people may not realize they have it and can spread it. Dr. Rutherford estimated that the number of cases might be more than twice that reported.

"[It's] harder to detect because people are like, 'I just have allergies. I'm going to work,'" Dr. Passaretti said. "And then you get other people infected."

Are Symptoms of BA.4 and BA.5 More Severe?

Not only are the symptoms from a BA.4 and BA.5 infection similar to other Omicron variants, but they also seem to have a similar severity, Dr. Passaretti and Dr. Rutherford said.

At Atrium Health hospitals, where Dr. Passarettti works, hospitalizations due to the BA.5 variant spiked in mid-2022. More infections were driving a higher number of COVID-19 hospitalizations rather than more severe symptoms. Though more people were in the hospital in 2022, the number of deaths nationwide plateaued from April to September 2022, according to the CDC.

"We aren't seeing at this point in time—although we continue to monitor closely—a steep increase in our number of ICU stays or deaths from COVID," Dr. Passaretti said. "But we are certainly seeing an increase in cases in the community, and that's spilling over to more patients admitted with COVID."

You can treat the milder symptoms—cough, sore throat, runny nose—at home. But if your oxygen levels drop and you start to feel dizzy or short of breath, you may need to get treatment for COVID-19 at a hospital.

Communities can avoid major complications and deaths from the BA.4 and BA.5 variants the same way as with any other variant.

"Rapid diagnosis, early diagnosis, and treatment is the way to go," Dr. Rutherford said.

As with the symptoms themselves, it was too early as of September 2022 to tell just how severely the variants might affect patients. In a White House press briefing, Dr. Walensky noted that people still need to be vigilant in staying up to date on COVID-19 vaccines and boosters.

"We know that vaccine effectiveness against severe disease and death remains high for other Omicron [types] and likely also for BA.4 and 5," Walensky said. "So, staying up to date on your COVID-19 vaccines provides the best protection against severe outcomes."

A Quick Review

Omicron BA.4 and BA.5 caused the vast majority of COVID-19 infections in 2022.

In the fall of 2022, experts weren't sure how severely the Omicron BA.4 and BA.5 subvariants would affect the U.S. population. Still, symptoms don't seem to be much different than for Omicron or other types of COVID-19 infection.

Both subvariants spread more quickly, maybe because people don't realize they are sick with the virus. Infected people may then go to work or other gatherings and spread the virus.

However, many of the more common Omicron BA.4 and BA.5 symptoms are not severe, and you can often treat them at home.