BA.3.2 COVID Variant: US Cases & Global Spread – What We Know

March 23, 2026 Dr. Michael Lee – Health Editor Health

The highly mutated SARS-CoV-2 variant BA.3.2 has been detected in the United States, according to a study published last week in the Morbidity and Mortality Weekly Report. The variant was identified in nasal swabs from four US travelers, clinical samples from five patients, three airplane wastewater samples, and 132 wastewater surveillance samples collected from 25 states.

First identified in a respiratory sample in South Africa in November 2024, BA.3.2 possesses approximately 70 to 75 substitutions and deletions in the gene sequence of its spike protein compared to the JN.1 variant and its descendant, LP.8.1 – the antigens currently used in updated COVID-19 vaccines. Researchers, led by scientists at the Centers for Disease Control and Prevention (CDC), described BA.3.2 as a “new lineage” genetically distinct from JN.1 lineages that have been circulating in the US since January 2024.

Detections of BA.3.2 began to increase in September 2025. The CDC’s Traveler-Based Genomic Surveillance program identified the first US case on June 27, 2025, in a traveler arriving from the Netherlands. From November 2025 to January 2026, the variant’s prevalence rose to approximately 30% of sequences analyzed in Denmark, Germany, and the Netherlands. The first US clinical specimen positive for BA.3.2 was documented on January 5, 2026.

As of February 11, BA.3.2 accounted for 0.19% of the 2,579 total genetic sequences collected in national surveillance starting December 1, 2025. Researchers cautioned that limited genomic detection and surveillance capabilities in many countries likely underestimate the true geographic spread of the variant. Phylogenetic analyses have identified two sublineages of BA.3.2, designated BA.3.2.1 and BA.3.2.2, indicating ongoing viral evolution.

The study authors noted that the mutations in BA.3.2’s spike protein could potentially reduce the effectiveness of protection conferred by prior vaccination or infection. Researchers at the Icahn School of Medicine at Mount Sinai recently published research on antibody responses to BA.3.2 and other variants, including LP.8.1, LF.7.1, NB.1.8.1, XFG, and BA.3.2, following vaccination with a monovalent mRNA vaccine. The CDC continues to use digital public health surveillance to monitor SARS-CoV-2 variants globally.

The researchers emphasized the need for continued genomic surveillance to track SARS-CoV-2 evolution and assess its potential impact on public health.