COVID-19 variant BA.3.2 is spreading quickly across US – a doctor explains what you need to know

A variant of COVID-19 called BA.3.2, which has circulated under the radar since late 2024, is now spreading quickly across the United States.

As a pulmonary and critical care doctor, I see many patients who are at high risk for severe COVID-19 due to chronic lung disease, as well as patients living with long COVID. All of them ask me how worried they should be about new variants of the virus.

There’s no sign so far that BA.3.2, nicknamed Cicada, is any more dangerous or causes more severe disease than the variants that were circulating in the winter of 2025-26. But because it’s significantly different from them, the current COVID-19 vaccine may not be as effective against it.

Where did the BA.3.2 variant come from?

BA.3.2 is descended from the omicron variant, which emerged in late 2021.

Compared to the current predominant strains of SARS-CoV-2, the virus that causes COVID-19, BA.3.2 carries 70 to 75 genetic changes in its spike protein, the part of the virus that helps it get into cells. The spike protein is also the part of the virus that vaccines rely on to coax people’s immune systems into recognizing the virus.

Researchers first identified BA.3.2 in November 2024 in Africa. It started its global trek in 2025 and had made it to 23 countries as of February 2026.

The first U.S. case was detected in a traveler coming into the U.S. in June 2025. Since then, it has been detected in patients and the wastewater systems of 29 states.

Wastewater monitoring is one of the best early methods of detecting strain shift, though the number of states submitting wastewater data to the CDC has declined since around 2022, after the height of the pandemic.

What makes BA.3.2 variant different?

All viruses change over time – and the type of virus that causes COVID-19 does so especially quickly. Every time the virus copies itself inside a cell, its DNA mutates. Most of these changes disappear, but occasionally one gives the virus an advantage over other variants, allowing that version to spread.

These changes make it harder for the immune system to recognize the virus.

Think of it like showing up to your 25th high school reunion and seeing people who have put on weight, dyed their hair and started wearing tinted contacts. You will recognize them, but it might take longer. Had you seen them every month or so for those 25 years, you would recognize them right away.

Similarly, changes to a virus’ DNA also affect how well vaccines work. Vaccines prime people’s immune systems by reminding them of what the virus looks like. Scientists design vaccines based on the most common versions of a virus circulating at a given time.

Current COVID-19 vaccines are made to protect against strains from the JN.1 lineage of the virus, which have been the most common strains in the U.S. since January 2024. However, BA.3.2 is the new kid in the block − it’s almost a complete stranger to residents of the U.S. It is different enough from the JN.1 strains that the vaccine may not do as good a job of priming the immune system against it, allowing it to evade detection.

This doesn’t mean you shouldn’t get a vaccine – a large body of evidence shows that they reduce hospitalizations and deaths from COVID-19. But a poorly matched vaccine simply won’t recognize the new variant as quickly, which means it takes longer for the immune system to mount its defense.

What dangers does the BA.3.2 variant pose?

Because people’s immune systems aren’t as good at detecting BA.3.2, this variant may infect people more widely, potentially leading to a spike in COVID-19 cases.

But even though BA.3.2 is spreading quickly, there’s no indication that it’s any more dangerous or that it causes more severe disease than the COVID-19 variants that have circulated widely over the past few years.

However, especially given that current vaccines may not be as effective against it, protection remains important. That’s particularly true for people with chronic health conditions, who can experience severe illness from a COVID-19 infection.

And while the number of people who develop long COVID has declined as the virus has changed since early in the pandemic, it still occurs in about 3 in 100 cases.

Protecting yourself and your community

People can take these commonsense steps to avoid getting or spreading COVID-19:

• First, wash your hands after using the bathroom, before preparing food or eating, and after being in contact with a sick person. Hand-washing decreases the chance of a respiratory infection by 16% to 21%.

• Second, if you feel unwell, stay home – not just to take care of yourself, but to prevent spreading disease. You may be hesitant to miss work or school, but the person sitting next to you might have a condition, such as cancer or chronic lung disease, that puts them at risk for severe infection, or they might live with someone who does.

• Third, get outside. Reducing your time in crowded environments reduces your chance of exposure.

• Finally, if you have concerns about your risk of developing a severe infection due to your own health conditions, talk to a trusted clinician who can offer advice that’s specific to your circumstances.