A new and genetically distinct Omicron variant of Covid-19, BA.3.2, has been identified in 29 US states and Puerto Rico, according to data from the Centers for Disease Control and Prevention. The variant, which carries dozens of new mutations, is under close watch by global health bodies but is not currently linked to more severe illness.
The variant, informally nicknamed “Cicada” for its pattern of emerging and re-emerging, was first detected in South Africa in November 2024. Genetic analysis suggests it may have emerged earlier, circulating at low levels as widespread testing diminished. It has since been found in at least 23 countries. In the United States, it accounted for just 0.55% of sequenced cases as of mid-March, but wastewater surveillance has confirmed its presence across numerous states.
A variant under monitoring, not alarm
The World Health Organization has classified BA.3.2 as a “Variant Under Monitoring” and its initial risk evaluation concluded it poses a “low additional public health risk” compared to other circulating strains. “The right response to BA.3.2 is serious attention, not alarm,” says Dr Jake Scott, a Stanford infectious disease expert who authored a systematic review of Covid vaccines for the New England Journal of Medicine.
Experts stress there is no evidence yet that BA.3.2 causes more severe disease. “BA.3.2 has not shown a sustained growth advantage over any other co-circulating variant, and no data indicate increased severity, hospitalisations or deaths associated with this variant,” Dr Scott said, summarising the WHO position. This assessment is central to the current public health understanding.
The variant’s profile is striking due to its high number of spike protein mutations—over 70 compared to the original virus—leading some researchers to theorise it may be the result of a “saltation event,” a sudden evolutionary leap potentially occurring during a prolonged infection. Despite this, its behaviour appears clinically consistent with other Omicron subvariants. Marc Veldhoen, an immunologist at the University of Lisbon, notes that “biologically no major differences have been reported or are expected: it is Omicron Sars-CoV-2.” He adds that describing it as “heavily mutated is relative; Sars-CoV-2 is nearly 30,000 base pairs long.”
In parts of Europe, BA.3.2 rose to account for around 30% of sequenced cases in countries like Denmark, Germany, and the Netherlands between late 2025 and early 2026, all without a signal of worse outcomes. In the UK, Public Health Wales has noted an increase, and early indicators suggest it and related sub-lineages are growing in prevalence.
Vaccines, immunity, and future updates
Current vaccines continue to provide robust protection against the most serious consequences of the virus, experts agree. “The question that actually matters is whether BA.3.2 meaningfully erodes protection against severe disease,” said Dr Scott. “As of now, all evidence shows that it doesn’t.”
Laboratory studies do indicate BA.3.2 exhibits “antigenic drift,” meaning antibodies from vaccination or prior infection may neutralise it less effectively than earlier Omicron strains. However, Dr Scott points out that immunity involves more than just antibodies. “Vaccines and prior infection also build a deeper layer of immune memory, one that goes beyond antibodies and can recognise and fight the virus even after it has mutated,” he said. This cellular immunity is a key reason protection against hospitalisation and death has remained resilient across variants.
Its mutations, however, have flagged it for discussion by the WHO’s vaccine composition group, meaning it will likely influence the design of future vaccine updates. “Vaccine researchers, on the other hand, should be continuing to track the variant in order to determine how to best update the vaccine,” added Professor Veldhoen.
Patterns in paediatric cases
One notable pattern emerging from global sequencing data is that BA.3.2 appears overrepresented in paediatric samples relative to adults in several countries. Dr Scott acknowledged this pattern “appears real” in databases like Gisaid, but urged caution in interpretation.
“I would be cautious about the leap from ‘more commonly sequenced in children’ to ‘preferentially infects children’ in any clinically meaningful sense,” he said. The disparity may reflect current testing biases: adults with mild infections are less likely to be tested and sequenced, while symptomatic children are more likely to be seen clinically and have their samples sequenced. Another possibility is that children have less accumulated exposure to previous variants, making them more susceptible to new ones.
Critically, there is no indication the variant causes more severe disease in children. “More importantly, there is no current signal that BA.3.2 is causing more severe disease in children,” Dr Scott stated, adding the pattern was worth noting but not catastrophising.
Public health advice remains consistent with earlier phases of the pandemic. The WHO continues to recommend staying up-to-date with vaccinations, mask-wearing and improved ventilation in high-risk settings, and practising good hygiene to prevent infection and related risks like long Covid. “The goal was never to prevent every infection. It was to keep people out of the hospital,” Dr Scott said. “That protection has proven more robust than the variant-by-variant headlines often suggest.”
