SARS-CoV-2 Variant BA.3.2, Nicknamed Cicada, Detected in 25 States and 23 Countries. Surveillance Continues.

Rabbit Trails

SARS-CoV-2 Variant BA.3.2, Nicknamed Cicada, Detected in 25 States and 23 Countries. Surveillance Continues.

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The Dispatch

The United States Centers for Disease Control and Prevention published a report in the Morbidity and Mortality Weekly Report on March 19, 2026, designating SARS-CoV-2 variant BA.3.2 as a variant under monitoring. The variant has been assigned the informal designation Cicada. It was first identified in South Africa in November 2024, remained at low levels of detection for approximately twelve months, and has since been identified in rising numbers across multiple countries. As of February 11, 2026, the most recent date for which complete CDC data is available, BA.3.2 has been detected in 132 wastewater surveillance sites across at least 25 states, in nasal swab samples from four international travelers, in three airplane wastewater samples, and in clinical samples from five patients. The variant has been identified in at least 23 countries. The World Health Organization listed it as a variant of monitoring on February 23, 2026.

BA.3.2 carries approximately 70 to 75 substitutions and deletions in its spike protein gene, compared to 30 to 40 in predecessor variants JN.1 and LP.8.1, which served as the basis for the 2025-2026 vaccine formulation. The CDC has assessed the variant as having immune escape potential — meaning antibodies produced by prior infection or current vaccines show reduced neutralization effectiveness in laboratory conditions. The variant is part of the Omicron lineage. No evidence has emerged that it causes more severe disease or higher mortality than other recent Omicron subvariants. Symptoms are consistent with standard COVID-19 presentation and are not clinically distinguishable from influenza, respiratory syncytial virus, or the common cold without testing. The CDC has not changed its core recommendations. Antivirals are expected to remain effective.

As of the week ending March 21, 2026, BA.3.2 was detected in approximately 11 percent of national wastewater samples, according to CDC monitoring data. WastewaterSCAN, a disease-tracking program operated by Stanford University, reported detection in 3.7 percent of its samples as of March 14. The dominant circulating strain in the United States remains XFG, which accounts for approximately 53 percent of samples. BA.3.2 has not yet reached a proportion sufficient for inclusion in the CDC’s variant proportion tracker. In Northern Europe, the variant reached approximately 30 percent of sequenced cases in Denmark, Germany, and the Netherlands during the late 2025 to early 2026 period. Overall COVID incidence in those countries was not reported as dramatically elevated relative to prior periods. The first U.S. detection occurred in June 2025, via a traveler arriving from the Netherlands at San Francisco International Airport. The first confirmed U.S. clinical patient sample was collected in January 2026. National prevalence in sequenced samples from December 2025 through February 2026 was approximately 0.19 percent.

The CDC’s wastewater surveillance program, which detected the variant’s presence across 132 monitoring sites in 25 states, operates by collecting samples from sewage, industrial discharge, and stormwater systems. It is the primary mechanism by which BA.3.2 has been tracked in the United States, given the reduction in formal clinical testing since the acute phase of the pandemic. The CDC is classified as a variant-under-monitoring designation, which indicates the agency is tracking the variant but has not assessed it as a variant of interest or a variant of concern. A reformulated vaccine targeting fall 2026 circulation is under development. Surveillance continues.