CDC tracks BA.3.2 Cicada COVID variant across 25 US states as WHO flags immune escape risk

A heavily mutated SARS-CoV-2 variant designated BA.3.2, informally referred to as “Cicada,” is under active surveillance by the United States Centers for Disease Control and Prevention and the World Health Organization following detections across 25 United States states and at least 23 countries. While overall COVID-19 case numbers in the United States remain comparatively low as of late March 2026, the variant’s unusual mutation profile has prompted formal classification by the World Health Organization and accelerated genomic monitoring across multiple continents.

The Centers for Disease Control and Prevention published a detailed surveillance report on 19 March 2026 in the agency’s Morbidity and Mortality Weekly Report, describing early detection data collected from November 2024 through February 2026. The report confirmed that BA.3.2 carries approximately 70 to 75 mutations and deletions in its spike protein gene sequence relative to the JN.1 and LP.8.1 variants, which are the antigens used in the 2025 to 2026 COVID-19 vaccine formulations. The Centers for Disease Control and Prevention described BA.3.2 as representing a lineage that is genetically distinct from the family of variants that has dominated global circulation in recent years.

How the BA.3.2 Cicada COVID variant emerged from a dormant Omicron branch and began spreading globally from South Africa in 2024

The Omicron variant family has dominated global SARS-CoV-2 circulation since late 2021, producing successive waves through sub-lineages including BA.2, BA.4, BA.5, and eventually the JN.1 lineage that formed the basis of most COVID-19 vaccines deployed from 2024 onward. BA.3, an earlier branch of the Omicron family, largely disappeared from circulation in early 2022 without achieving significant global spread. BA.3.2 is a descendant of that earlier branch, meaning it does not share the evolutionary pathway that produced the JN.1 family now targeted by current vaccines.

The first BA.3.2 lineage sequence was detected in a respiratory sample collected on 22 November 2024 in South Africa. South African investigators isolated SARS-CoV-2 from a nasopharyngeal swab collected from a five-year-old boy and designated the sequence as BA.3.2.1 under Pango nomenclature. On 17 March 2025, BA.3.2 was detected in Mozambique, followed by detections in the Netherlands on 12 April 2025 and in Germany on 29 April 2025. Following those initial detections, reported cases remained infrequent before beginning to rise notably from September 2025 onward.

Scientists have theorised that BA.3.2 likely accumulated its large number of mutations over an extended period inside a chronically infected individual before re-entering general circulation, a process referred to in virology as cryptic evolution. The variant’s informal nickname “Cicada” was assigned by T. Ryan Gregory, a professor of evolutionary biology at the University of Guelph, drawing on the insect’s pattern of spending years underground before a sudden mass emergence. Gregory has previously coined colloquial names for several other SARS-CoV-2 variants. The first detection in a United States traveller occurred in June 2025 through the Centers for Disease Control and Prevention’s Traveler-Based Genomic Surveillance program, in a participant arriving from the Netherlands at San Francisco International Airport. Clinical patient detections in the United States were first reported in December 2025.

What CDC wastewater surveillance and sequencing data reveals about BA.3.2 spread across 25 United States states as of March 2026

As of 12 March 2026, BA.3.2 had been identified in nasal swabs from six United States travellers, three airplane wastewater samples, 29 patients, and 260 wastewater samples in 29 states and Puerto Rico. The variant’s prevalence among 5,238 sequences collected between 1 December 2025 and 12 March 2026 stood at 0.55 percent. Data from WasteWaterSCAN, a Stanford University-led disease tracking program, showed BA.3.2 present in 3.7 percent of wastewater samples nationally as of 14 March 2026. Variant XFG remains the dominant strain at 53 percent of national wastewater samples, followed by LF.7 at 10.3 percent. BA.3.2 is not yet represented in the Centers for Disease Control and Prevention’s variant proportion tracker, which requires a higher case threshold for inclusion.

The Centers for Disease Control and Prevention’s data from 11 February 2026 confirmed BA.3.2 detection across 25 states: California, Connecticut, Florida, Hawaii, Idaho, Illinois, Louisiana, Maine, Michigan, Maryland, Massachusetts, Missouri, New Hampshire, New Jersey, Nevada, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, Utah, Vermont, Virginia, and Wyoming. Detections have been identified through multiple surveillance channels, including traveller testing, clinical samples from patients, and wastewater monitoring sites.

Why the 70 to 75 spike protein mutations in BA.3.2 raise immune escape concerns for vaccine developers and global health authorities

The spike protein is the primary mechanism through which SARS-CoV-2 attaches to human cells and is also the exclusive target of all approved COVID-19 vaccines. A large number of mutations in this protein region can reduce the ability of antibodies, whether generated through vaccination or prior infection, to recognise and neutralise the virus. The Centers for Disease Control and Prevention described BA.3.2’s spike protein changes as having the potential to reduce protection from prior infection or vaccination. Laboratory studies cited in the agency’s Morbidity and Mortality Weekly Report indicated that BA.3.2 effectively evaded COVID-19 antibodies due to its spike protein configuration.

The World Health Organization classified BA.3.2 as a “variant under monitoring” in December 2025, a classification tier that indicates active surveillance is warranted without reaching the threshold of a variant of concern or variant of interest. The World Health Organization added BA.3.2 to its formal variants of monitoring record on 23 February 2026. Internationally, BA.3.2 detections rose sharply in September 2025. In Denmark, Germany, and the Netherlands, the variant accounted for approximately 30 percent of reported sequences between November 2025 and January 2026. Despite that concentration in Northern Europe, BA.3.2 has not rapidly displaced other variants. Instead, it has co-circulated with multiple JN.1 descendant lineages across the countries where it has been detected.

Phylogenetic analysis has confirmed the emergence of two distinct BA.3.2 sublineages, BA.3.2.1 and BA.3.2.2, indicating the variant continues to evolve. The Centers for Disease Control and Prevention has cautioned that limited genomic surveillance capacity in many countries means the actual geographic extent of BA.3.2 spread is likely underrepresented in current detection data. Laboratory studies on the BA.3.2.1 and BA.3.2.2 sublineages found reduced lung cell entry efficiency compared to other circulating strains, a characteristic that may limit the variant’s capacity to achieve broad dominance despite its immune evasion properties.

What clinical data shows about BA.3.2 Cicada variant severity, symptoms, and hospitalisation risk in early 2026

Current clinical data from the countries where BA.3.2 has achieved its highest circulation rates does not indicate that the variant causes more severe illness than earlier Omicron sub-lineages. Symptoms reported in patients testing positive for BA.3.2 have largely mirrored those associated with other circulating COVID-19 variants, including cough, fever, fatigue, sore throat, headache, muscle aches, and congestion. Some patients have reported gastrointestinal symptoms or skin rashes, though these remain uncommon. Several cases have also been associated with severe sore throat, a symptom pattern that has appeared across a number of recent SARS-CoV-2 variants. Health officials have confirmed there is no data indicating BA.3.2 produces more severe illness or elevated hospitalisation rates in populations where it has achieved the greatest prevalence.

While some hospitalised patients with pre-existing health conditions have tested positive for BA.3.2, the Centers for Disease Control and Prevention stated that these cases do not necessarily indicate that the variant is the cause of more severe disease outcomes. The public health burden of COVID-19 in the United States between October 2025 and March 2026 included an estimated 390,000 to 550,000 hospitalisations and 45,000 to 64,000 deaths across all circulating variants.

How current COVID-19 vaccines and approved antiviral drugs are expected to perform against the BA.3.2 Cicada variant in 2026

The COVID-19 vaccine formulations updated for the 2025 to 2026 season target the LP.8.1 variant, which was the dominant strain at the time vaccine compositions were selected. LP.8.1 has since declined in prevalence. Laboratory data indicated that the current 2025 to 2026 vaccine formulation produced the lowest antibody neutralisation against BA.3.2 among all tested variants. Public health agencies and immunologists have stressed, however, that reduced protection against infection does not translate directly to reduced protection against severe disease. Protection against hospitalisation and death from COVID-19 is generally expected to hold at higher levels even when antibody neutralisation against a specific variant is diminished.

The fall 2026 vaccine formulation cycle is expected to consider whether BA.3.2 should be incorporated as a target antigen, depending on the variant’s trajectory in the coming months. Existing antiviral treatments retain their effectiveness against BA.3.2. Paxlovid, the combination antiviral medication used in high-risk COVID-19 patients, targets a different component of the virus that is not subject to the rapid mutation occurring in the spike protein. Remdesivir and Molnupiravir are also considered likely to retain effectiveness against currently circulating variants, including BA.3.2.

The Centers for Disease Control and Prevention has reinforced standard public health guidance in response to BA.3.2 detections: individuals who test positive for COVID-19 should isolate until symptoms resolve and a negative test is confirmed. High-quality mask use, ventilation improvements, and uptake of available boosters remain the primary recommended measures. The agency characterised the monitoring of BA.3.2’s spread as providing valuable information about the potential for the new SARS-CoV-2 lineage to alter the landscape of immunity in the broader population.

What the emergence of BA.3.2 Cicada means for global COVID-19 surveillance, vaccine policy, and public health response in 2026

• The SARS-CoV-2 variant BA.3.2, designated “Cicada,” carries approximately 70 to 75 spike protein mutations, making it genetically distinct from the JN.1 and LP.8.1 lineages targeted by the 2025 to 2026 COVID-19 vaccine formulations, and has been detected in 25 United States states and at least 23 countries as of March 2026.
• The World Health Organization classified BA.3.2 as a “variant under monitoring” in December 2025, and the Centers for Disease Control and Prevention published formal surveillance findings on 19 March 2026, confirming the variant’s presence across multiple surveillance channels including traveller testing, clinical samples, and national wastewater monitoring.
• Laboratory studies indicate BA.3.2 effectively evades existing COVID-19 antibodies, raising immune escape concerns; however, current data from countries where the variant has reached 30 percent of sequenced cases, including Denmark, Germany, and the Netherlands, shows no evidence of increased disease severity or elevated hospitalisation rates.
• Two BA.3.2 sublineages, BA.3.2.1 and BA.3.2.2, have been confirmed through phylogenetic analysis, indicating ongoing viral evolution, though both sublineages have demonstrated reduced lung cell entry efficiency compared to other strains, which may limit their capacity for rapid dominance.
• Existing antiviral treatments including Paxlovid, Remdesivir, and Molnupiravir are expected to retain effectiveness against BA.3.2, and current vaccine formulations continue to provide meaningful protection against severe disease and hospitalisation even as antibody neutralisation against the variant is reduced.