The SARS-CoV-2 variant designated BA.3.2 — informally known as “cicada” — entered the United States through San Francisco International Airport. On June 27, 2025, the CDC’s Traveler-Based Genomic Surveillance program detected the strain in a passenger arriving from the Netherlands. Since then, the virus has spread across the country largely under the radar.
What the CDC Report Found
On March 19, 2026, the CDC published a detailed report in Morbidity and Mortality Weekly Report. BA.3.2 has been detected in wastewater samples across 25 states, in swabs from four travelers, in clinical specimens from five patients, and in three aircraft water samples. Globally, the variant has been identified in at least 23 countries. In Denmark, Germany, and the Netherlands, it accounted for roughly 30% of sequenced samples by early 2026.
In the United States, BA.3.2 still represents less than 1% of all sequenced specimens. But wastewater surveillance picked it up before clinical testing did. Its spread began in September 2025, with detections peaking during the week of December 7.
What Makes This Variant Different
BA.3.2 carries between 70 and 75 mutations and deletions in its spike protein relative to JN.1 — the variant on which current 2025–2026 season vaccines are based. The CDC characterizes it as a genetically novel SARS-CoV-2 lineage, distinct from every strain circulating in the United States since January 2024.
Laboratory studies show that 2025–2026 vaccines neutralize BA.3.2 less effectively than other variants under evaluation — meaning a higher likelihood of breakthrough infections in vaccinated individuals. The vaccines, however, continue to protect against severe illness, hospitalization, and death.
There is also a potentially reassuring finding. Lab data suggest BA.3.2 is less efficient at penetrating lung cells than its predecessors. Of the five confirmed clinical cases in the United States, two patients were hospitalized — both elderly, both with underlying conditions. All five survived.
What Bay Area Residents Should Know
Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center, told SFGATE that BA.3.2 is “substantially different” from previous variants. Specialists at UC San Francisco note that COVID-19 has not yet settled into a predictable seasonal pattern — the virus mutates too quickly and continues to surge outside the traditional winter cycle.
Symptoms of BA.3.2 are consistent with other Omicron variants: cough, fever, fatigue, headache, and sore throat. Loss of smell is less common than in the early pandemic years. Antiviral medications remain effective.
The CDC recommends staying current with the updated 2025–2026 vaccine. That guidance is especially important for older adults and people with chronic conditions — the groups that current data show are most at risk of hospitalization.
This article is for informational purposes only and does not constitute medical advice. Consult a licensed healthcare professional for diagnosis or treatment.