New COVID Variant BA.3.2 Detected in California Wastewater | Immune Escape Concerns

A new variant of the coronavirus, dubbed BA.3.2, is being detected in California wastewater, signaling continued evolution of the virus even as overall COVID-19 activity remains low in the state, according to data released this week.

The Centers for Disease Control and Prevention (CDC) reported on March 19 that BA.3.2 has also been identified in a small number of patients and international travelers within the United States. The initial U.S. Detection occurred last June with a traveler arriving at San Francisco International Airport.

What distinguishes BA.3.2 is its significant genetic divergence from recent strains. The CDC indicates the variant carries approximately 70 to 75 mutations in its spike protein compared to earlier versions of the virus. Scientists caution that We see currently too early to determine the real-world implications of these changes, but some alterations may contribute to partial immune evasion from prior infections or vaccinations.

As of mid-March, BA.3.2 accounted for 0.55% of sequenced U.S. Cases and has not yet surpassed currently circulating variants in prevalence. The California Department of Public Health reports that COVID-19 activity “remains very low statewide.”

Current evidence suggests BA.3.2 does not cause a different type of illness than other recent variants. Symptoms appear to be consistent with mild, cold-like presentations, making it difficult to differentiate from other respiratory infections.

The pattern of detection – first appearing in wastewater surveillance systems – mirrors trends observed throughout the pandemic, where new variants are often identified in sewage data weeks before widespread patient detection.

Dr. Peter Chin-Hong, an infectious disease specialist at UCSF, emphasized that the greater risk may not be the variant itself, but rather public complacency. “COVID-19 may feel like it is fading into the rearview mirror, but the virus has not returned the favor,” he said. “Complacency, not just mutation, is now one of our greatest risks.”

Alongside the emergence of BA.3.2, the CDC is also tracking a rise in measles cases across the United States. As of late March, measles is spreading in 31 states, raising concerns about declining vaccination rates and potential outbreaks.