The SARS-CoV-2 subvariant BA.3.2, nicknamed "Cicada," has been detected in at least 25 U.S. states and is disproportionately infecting children between the ages of 3 and 15, according to CDC surveillance data published this week. [1] It is the first COVID variant to show a clear age preference for pediatric populations, a pattern that variant trackers identified in New York City wastewater and clinical data before federal agencies issued formal guidance. [2]

An analysis by independent variant researcher Ryan Hisner, using NYC clinical sequencing data, found that children aged 1 to 14 accounted for 38 percent of confirmed BA.3.2 infections in the most recent reporting week -- a share far exceeding their proportion of the general population. [2] The mechanism is not yet understood. Hypotheses range from immune imprinting -- adults carry antibodies from prior infections and vaccinations that partially neutralize BA.3.2, while younger children do not -- to a surface protein mutation that may exploit receptors more prevalent in developing airways. [1]

The reassuring news: Cicada does not appear more severe than existing circulating strains. Hospitalization rates among infected children remain low, and no pediatric ICU surge has been reported. [1] The concerning part is the unknown. A variant that preferentially infects an age group with the lowest vaccination rates and the highest density of social contact -- schools, daycares, playgrounds -- has transmission advantages that clinical mildness does not offset.

The CDC has not recommended any changes to masking or school policies.

-- NORA WHITFIELD, Chicago