CDC Tracks 'Cicada' COVID Variant in 25 States Amid Immune Escape Fears

The Centers for Disease Control and Prevention revealed Thursday that the SARS-CoV-2 variant BA.3.2, nicknamed 'Cicada' for its pattern of emergence and disappearance, has been detected in 132 wastewater samples from 25 states, alongside nasal swabs from four U.S. travelers, clinical samples from five patients, and three airplane wastewater samples.[1][3][4] First identified in a South African respiratory sample on November 22, 2024, the strain reached the U.S. on June 27, 2025, via a traveler from the Netherlands through the CDC's Traveler-Based Genomic Surveillance program.[3][4] Detections surged starting September 2025, with the variant now confirmed in 23 countries.[4] BA.3.2, a divergent Omicron descendant with over 70 mutations—specifically 70 to 75 substitutions and deletions in its spike protein compared to the JN.1 lineage—poses potential immune escape risks.[1][3][4] Laboratory studies show it efficiently evades antibodies, which could diminish protection from prior infections or vaccines like the 2025-2026 LP.8.1-adapted mRNA and JN.1-adapted protein formulations.[3] Despite this, it accounts for just 0.19% of U.S. infections and shows no rise in hospitalizations or severe cases so far.[1] Globally, it comprises about 8% of variants, per World Health Organization data.[1] CDC Director Dr. Mandy Cohen emphasized multimodal surveillance—including genomic sequencing, wastewater monitoring, and the National SARS-CoV-2 Strain Surveillance (NS3) system—to track BA.3.2's evolution.[3][5][6] "Continued genomic surveillance is needed to track SARS-CoV-2 evolution and determine its potential effect on public health," CDC researchers wrote in a Morbidity and Mortality Weekly Report published last week.[3][4] The agency provides weekly variant proportion estimates via empiric and Nowcast models every Tuesday.[6] Like recent subvariants Nimbus and Stratus, BA.3.2's mutations may alter transmissibility and immune response, but officials report no immediate surge in cases.[2] The CDC urges vigilance without new guidelines yet, focusing on vaccine updates if needed to counter antigenic diversity.[3] As COVID-19 activity could rise seasonally with immune-evading strains, robust data will shape responses and vaccine reformulations.[3]