A highly mutated strain of COVID-19, designated as variant BA.3.2 and nicknamed “Cicada,” is seeing a rapid increase in prevalence across the United States. New data indicates that the variant is gaining ground quickly, moving from a negligible presence in mid-March to a significant portion of detected infections by early April.
The surge in US cases of COVID variant ‘Cicada’ is most evident in wastewater surveillance, which often provides a more comprehensive view of community spread than individual clinical testing. According to data from WasteWaterSCAN, a surveillance tool led by Stanford University, the Cicada variant now accounts for more than 20% of tested COVID infections as of early April.
This represents a sharp climb from the middle of March, when the Centers for Disease Control and Prevention (CDC) first released reports showing the variant accounted for less than 4% of U.S. Cases. The increase of more than 15 percentage points in a matter of weeks suggests a high level of transmissibility for this specific lineage.
Global Spread and the Path to the U.S.
The Cicada variant did not originate in the U.S. But has been tracked globally for several months. Health officials from the World Health Organization (WHO) and the CDC first flagged the strain earlier this year after it was identified in at least 23 countries.
Before its rise in North America, the variant had already established a strong foothold in Eastern Europe. In some locales within that region, BA.3.2 accounted for up to 30% of cases. The transition from a localized European presence to a widespread U.S. Increase follows a pattern seen with previous “variants of interest,” where mutations that allow the virus to bypass existing immunity facilitate rapid international transmission.
As a physician, I have seen this cycle repeat with various Omicron sublineages. When a virus is described as “highly mutated,” it typically refers to changes in the spike protein—the part of the virus that attaches to human cells. These mutations can potentially make the virus more efficient at infecting cells or more adept at evading antibodies produced by previous infections or vaccinations.
Tracking the Transmission Timeline
The speed of the Cicada variant’s ascent in the U.S. Can be broken down by the following key milestones:
| Period | Estimated U.S. Prevalence | Observation Source |
|---|---|---|
| Mid-March | Less than 4% | CDC Report |
| Late March | Rising Trend | Global Surveillance |
| Early April | More than 20% | WasteWaterSCAN |
What This Means for Public Health
The primary concern for health providers when a new variant rises so quickly is whether the increase in cases is accompanied by an increase in severity. While the transmission data is clear, the clinical profile of BA.3.2—including whether it causes more severe respiratory distress or different symptomatic presentations—is still being analyzed by genomic researchers.
Wastewater monitoring is a critical tool in this process because it captures data from the entire population, including those who are asymptomatic or who do not have access to healthcare and therefore would not appear in clinical test counts. The jump to 20% indicates that the virus is circulating widely in the community, regardless of whether people are reporting symptoms to their doctors.
For the general public, the rise of the Cicada variant underscores the importance of staying current with boosters. Because these mutations often target the “lock and key” mechanism of the virus, updated vaccines are designed to provide a closer match to the circulating strains, reducing the likelihood of severe disease even if “breakthrough” infections occur.
Understanding the Risks and Constraints
While the data shows a clear upward trajectory in transmission, there are several unknowns that health officials are currently working to resolve:
- Immune Evasion: To what extent does BA.3.2 bypass antibodies from the latest vaccine formulations?
- Symptom Profile: Are there distinct symptoms associated with Cicada compared to previous Omicron subvariants?
- Hospitalization Rates: Is the 15% increase in cases leading to a proportional increase in hospital admissions?
These questions are typically answered through a combination of genomic sequencing and clinical observation. Until more data is available, the baseline advice remains focused on mitigation: improving indoor ventilation, using high-quality masks in crowded spaces, and maintaining vaccination schedules.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Please consult a healthcare provider for personalized medical guidance or treatment.
Public health agencies are expected to provide further updates as more genomic sequencing data from April becomes available, which will aid determine if BA.3.2 will become the dominant strain in the U.S. For the spring season. Stay tuned for official guidance from the CDC regarding updated booster recommendations.
Do you have questions about the new variant or your local health guidelines? Share your thoughts in the comments below.
