Cicada COVID Variant Spreads Rapidly, Now Detected Across 25 States

Sewage data offered the clearest early signal: during the week ending March 21, a COVID-19 variant called BA.3.2 appeared in at least 11% of national wastewater surveillance samples, according to CDC monitoring data. For a strain that spent most of 2024 and 2025 replicating quietly beneath the surface of mainstream surveillance, the figure represents a measurable and continuing climb.

The CDC confirmed BA.3.2's presence in at least 25 states as of February 11, with Stanford University's WastewaterSCAN disease-tracking program logging rising detections in sewage samples across the country. The CDC's Morbidity and Mortality Weekly Report documented the footprint in granular detail: positive results from nasal swabs collected from four U.S. travelers, clinical samples from five patients, three airplane wastewater samples, and 132 wastewater surveillance samples spanning all 25 states.

The variant's defining characteristic is its spike protein. BA.3.2 carries between 70 and 75 mutations in the surface structure the coronavirus uses to enter human cells, far exceeding the mutational profile of the dominant strains it quietly shadowed for over a year. Andrew Pekosz, Ph.D., a virologist at the Johns Hopkins Bloomberg School of Public Health, said those mutations set BA.3.2 apart from JN.1 and LP.8.1, the strains current COVID-19 vaccines were formulated to target. "It was under the radar, replicating, until it started to spread more from person to person," Pekosz said.

The CDC described BA.3.2 as having "immune escape characteristics," meaning its mutations may help it partially sidestep immunity from prior vaccination or infection. Authors of the MMWR report framed the genomic stakes plainly: BA.3.2 is "a new lineage of SARS-CoV-2, genetically distinct from the JN.1 lineages (including LP.8.1 and XFG) that have circulated in the United States since January 2024." The World Health Organization designated it a "variant under monitoring" on December 5, 2025, citing substantial antibody escape, while noting vaccines are still expected to protect against severe disease.

Experts are not raising alarms over severity. Adolfo García-Sastre, director of the Global Health and Emerging Pathogens Institute at Mt. Sinai, said "it can still cause problems, of course, but it's not a more problematic strain than previous ones," adding there is no evidence of increased hospitalizations in countries where the variant is most prevalent. Pekosz was similarly measured: "It's increasing, but it hasn't really caused a huge surge of infections anywhere."

The "cicada" nickname came from T. Ryan Gregory, Ph.D., a professor of evolutionary biology at the University of Guelph who previously named variants including "pirola" and "stratus." Like its insect namesake, BA.3.2 spent years developing underground before surfacing. Its ancestor, BA.3, never fully vanished after fizzling out years ago; dozens of additional mutations eventually produced BA.3.2, which has since branched into two subvariants, BA.3.2.1 and BA.3.2.2.

The variant's first confirmed U.S. detection came on June 27, 2025, when a respiratory sample collected at San Francisco International Airport from a traveler arriving from the Netherlands tested positive, per the CDC. Detections began climbing in September 2025. The CDC has reported BA.3.2 is now driving roughly 30% of cases in Denmark, Germany and the Netherlands, and at least 23 countries had reported the variant as of February 11.

How much of that spread is visible inside the United States remains uncertain. "There are still a lot of unknown questions about how prevalent it is in the U.S., because surveillance has been reduced a lot," said García-Sastre. With clinical monitoring thinned out, wastewater carries much of the diagnostic weight, and the 11% national share recorded the week of March 21 may already be an undercount of a variant that is, by any measure, no longer keeping quiet.