Overview
- Follow-up CDC surveillance through March 12 reports BA.3.2 in 260 wastewater samples across 29 states plus Puerto Rico, with detections rising to 0.55% of sequenced U.S. specimens and 29 patient cases identified.
- BA.3.2 carries about 70 to 75 changes in the spike protein compared with JN.1 and LP.8.1, and lab studies show the 2025–26 vaccine generated the lowest neutralizing antibodies against it among tested variants.
- The lineage was first identified in South Africa in November 2024 and reached the U.S. through traveler screening at San Francisco International Airport in June 2025, with reports now from at least 23 countries and up to roughly 30% of sequenced cases in parts of Europe without a surge in overall infections.
- CDC analyses have logged two offshoots, BA.3.2.1 and BA.3.2.2, and early lab work suggests reduced lung cell entry that could limit spread, prompting continued genomic and wastewater monitoring rather than emergency action.
- Public health guidance stresses that current vaccines still help prevent severe disease, especially for older adults and people with underlying conditions, and that wastewater often flags new variants weeks before clinical sequencing as routine patient sampling has declined.