A new omicron subvariant has been making headlines after gaining ground in early July in about 10 countries, including India, Australia, Germany and the U.S.
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Known as BA.2.75, this subvariant was first detected in India in early May and appears highly transmissible, leading doctors to believe it could be an up-and-coming variant of concern that could eventually compete with the BA.5 subvariant — now the most dominant strain of omicron that causes COVID-19 in the U.S.
Will this mean we could be seeing another wave of coronavirus infections in the fall? It’s too soon to tell, but as researchers continue to study the development of BA.2.75, it’s important to understand how and why these subvariants continue to evolve beyond their original mutations.
Microbiologist and pathologist Daniel Rhoads, MD, explains how subvariants work and what the latest news could mean for a potential future surge.
How many COVID-19 variants are there?
The Centers for Disease Control and Prevention (CDC) monitors all variants and subvariants of the original SARS-CoV-2 virus circulating in the U.S. The original virus has gone through several mutations since it was first detected in 2019 at the start of the COVID-19 pandemic. As of July 14, 2022, the CDC has been monitoring 12 variants, including:
- Delta: Once the dominant variant in the U.K. and the U.S., it is now no longer a “variant of concern.”
- Omicron: This variant became a variant of concern last winter when it was responsible for a global surge that began in November 2021. The U.S. was averaging more than 800,000 new cases a week of COVID-19 by the middle of January, according to The Washington Post. It’s now responsible for more than 65% of cases in the U.S.
According to the CDC, the omicron variant spreads faster and more easily than the original virus and the delta variant — and so far, that remains true as it continues to evolve with several subvariants that include BA.5 and BA.2.75.
The latest subvariants: BA.5 and BA.2.75
According to the World Health Organization (WHO), BA.2.75 was first detected in India in early May 2022, and has since been detected in more than 10 countries, including the U.S.
“BA.2.75 is a variant that has emerged recently,” says Dr. Rhoads. “We’re keeping close eyes on it, but we don’t have much more information just yet.”
BA.5 on the other hand is now the dominant omicron subvariant in the U.S., according to the CDC.
“The symptoms are generally the same or similar, but the caveat is that the symptoms can look different in any one individual,” notes Dr. Rhoads.
That means you can be asymptomatic, or have any number of symptoms that include:
- Fever or chills.
- Shortness of breath or difficulty breathing.
- Muscle or body aches.
- New loss of taste or smell.
- Sore throat.
- Congestion or runny nose.
- Nausea or vomiting.
How one person handles infection from BA.5 may be entirely different from how someone else handles it, so it’s important to remain aware of any new symptoms you experience.
What can you do to minimize infection?
The same protocols apply to BA.5 that have applied to every other variant and subvariant of the coronavirus: The best preventive measures include getting vaccinated, wearing a mask during times of high transmission, staying 6 feet apart, washing hands often and avoiding people who are sick.
How and why viruses mutate
Viruses are ever-changing in an effort to survive and spread. All viruses are made up of a bundle of genetic material (either DNA or RNA) that’s covered by a protective coating of proteins. Once a virus gets into your body — usually through your mouth or nose — it latches onto one of your cells. The virus’s DNA or RNA then enters your cell, where it can make copies of itself that go off and infect other cells. If the virus can copy itself and hijack enough of your cells without being wiped out by your immune system, that’s how you get sick.
With each new mutation that occurs in a virus, new characteristics arise. Some of these mutations cause the virus to stop working effectively, forcing them to die off or become less transmissible. Other mutations can cause the virus to become less detectable by our immune systems, become more transmissible or evade our immune system’s memory.
“I think of it like a dice roll: Every time somebody is infected, there are millions of new viral particles that are put out and there are some mistakes that can be made during the replication of the virus,” explains Dr. Rhoads. “Sometimes, these mistakes are actually helpful. But usually, they’re not.”
The CDC compares the mutation process to the branches of a tree: With each new mutation, a new branch grows, allowing the virus to grow in new directions. From those branches, there are stems, or subvariants, that are further mutations made on the backbone of the main variant. BA.2.75 and BA.5, for example, are mutations of the omicron “parent” virus.
“BA.5 has a lot of mutations in its spike protein,” says Dr. Rhoads. “It’s thought that those mutations likely provide some immune escape, meaning if you have an underlying immunity due to vaccination or previous infection, this virus seems like it looks different enough that it can still cause infection.”
You can also think of variants, subvariants and virus lineages like a car.
“The original virus, SARS-CoV-2, is like the make of a car,” explains Dr. Rhoads. “Then, there are different models that come out that are a little bit different, even though it’s from the same designer and it’s basically the same thing. Omicron is a model of the original virus.”
And when you add special features to that unique make and model, you’ve got yourself a new subvariant.
Will there be a surge in the fall or winter?
The chances of another surge are high. The CDC provides a helpful weekly update on current and emerging variants. As of July 9, 2022, BA.5 is responsible for more than 65% of COVID-19 cases in the U.S., making it the current dominant variant. Those numbers only take into account the number of cases that have been reported, potentially leaving out a wide swath of cases that are overlooked thanks to the availability of at-home testing.
“Since home tests have become available, we’ve seen less demand for testing in the laboratory. The demand isn’t what it was six months ago,” says Dr. Rhoads. “So, it’s harder to recognize exactly what’s happening in the population because home tests may not be reported to anybody except their family.”
In short, as the number of cases continue to rise in relation to BA.5 and other emerging subvariants like BA.2.75, the potential for another surge is possible.
“Each of the last two winters, we’ve seen big peaks in the U.S., and I wouldn’t be surprised if that happens again this winter,” he adds.
Does the vaccine protect against variants?
In the end, the shape-shifting nature of the coronavirus (and all viruses) is something that experts across the world are keeping a close eye on, but it’s not something you should expect to change the course of the pandemic overnight.
However, the contagiousness of newer variants and subvariants are all the more reason to stay careful even as most states roll back social distancing guidelines. Only 67% of U.S. adults are fully vaccinated.
The CDC says the COVID-19 vaccines that are authorized for emergency use (Johnson & Johnson) or fully approved (Moderna and Pfizer-BioNTech) in the U.S. are highly effective at preventing severe disease and death. And while breakthrough infections will occur, the number of cases that result in serious illnesses, hospitalizations or death are very low.
Just in June, the FDA recommended including omicron components in COVID-19 vaccines and boosters this fall in an effort to increase protection against emerging and dominant omicron subvariants like BA.5 and BA.2.75.
“These new waves of infections show that the pandemic is not close to being over yet,” Dr. Rhoads says. “At this time, vaccination has proven to be our most effective tool, and vaccines are readily available for many children and adults in the U.S. Vaccinations are our best defense against severe disease that can be caused by these emerging variants.”