New Covid-19 Variant BA.3.2 Is Spreading and May ‘Evade Immunity,’ CDC Warns

Scientists at the Centers for Disease Control and Prevention are tracking a new covid-19 variant with mutations to its spike protein, which, they report, “have the potential to reduce protection from a previous infection or vaccination.”

Officials first detected BA.3.2, an Omicron descendant, in the United States last summer at San Francisco International Airport while conducting routine traveler-based genomic surveillance on a passenger arriving from the Netherlands. But starting this December, at least five cases of BA.3.2 have since been detected in hospital patients across four unidentified U.S. states, including a young child who received outpatient care. While all five patients survived, CDC officials are still monitoring the spread of BA.3.2—in no small measure because of the new lineage’s potential to “evade immunity.”

Right now, BA.3.2 only accounts for a minute 0.55% of covid-19 cases among the 5,238 genetically sequenced cases reviewed by the CDC between December 1, 2025, and March 12, 2026. However, this novel spike protein variant has already cropped up in 132 wastewater surveillance samples from 25 far-flung states across the country—including California, New York, Wyoming, Missouri, and Hawaii. The pattern suggests BA.3.2 might be spreading faster than the current genomic data might indicate.

CDC researchers said it was too early to tell if BA.3.2 will increase the severity of covid-19 as an illness or heighten the strain on America’s health care system. Fortunately, however, emerging cases of the new variant have not yet corresponded to any notable rise in covid-related deaths.

Who is most at risk?

Deaths from covid-19 in the U.S. continue to number over 100,000 cases per year, according to the most recent CDC analysis, with the vast majority of those deaths shouldered by Americans over the age of 65.

David C. Grabowski, a professor of health care policy at Harvard Medical School, advised in an editorial on the latest CDC mortality data that older adults should “look to avoid overcrowded nursing homes and other group living environments where covid-19 can spread quickly.” Instead, he added, “They should seek out settings with single occupancy rooms, better ventilation, and improved infection control practices.”

While the human cost wrought by covid-19 is far down from the heights of the pandemic years—when it likely killed over 20 million people worldwide, including at least a million across the U.S.—the virus is still infecting tens of millions of Americans each year.

The new data on BA.3.2 does appear to indicate, anecdotally, that it too is mainly a concern for the elderly and other immunocompromised individuals.

The CDC reported that two of the first three hospital patients detected with BA.3.2 this past winter were older adults already coping with preexisting chronic health issues, including one patient who had been admitted four days earlier for a heart condition.

The variant is spreading internationally

CDC investigators currently suspect that the BA.3.2 lineage may have emerged in South Africa, where it was first recorded in November 2024 via a nasal swab of a five-year-old boy. Since then, according to the CDC’s Morbidity and Mortality Weekly Report, the variant has cropped up in 23 countries, including Mozambique, the Netherlands, and Germany.

The variant appears to be spreading fastest in Europe, where it constitutes 30% of new cases sequenced in Denmark, Germany, and the Netherlands, although it has not yet led to a higher number of total covid-19 cases in those nations.

German researchers writing in The Lancet found that BA.3.2 beat six other covid variants at evading antibodies produced by the reigning (2025–2026) LP.8.1-adapted mRNA covid-19 vaccine—which is, perhaps, as good an explanation as any for the new variant’s rapid European tour.

The CDC cautioned that its current analysis, however, might be underestimating the current spread of BA.3.2 because many countries have “limited genomic detection and surveillance capacities.”

By their current assessment, BA.3.2 most likely entered the U.S. via “multiple independent domestic introductions” based on airport wastewater and traveler samples linked to Japan, Kenya, the Netherlands, and the United Kingdom.