Additionally, the detection of measles-specific IgM in 13% of children in our study, along with elevated neutralizing antibody titers in the mother cohort, suggests ongoing virus circulation within the community—a finding consistent with the continued reporting of significant measles cases in India.1,14,15 This concern extends beyond India, as importation remains a primary driver of measles outbreaks globally, including recent outbreaks in the US.16 India, therefore, faces a dual challenge: inadequate vaccine coverage and suboptimal immune responses even among fully vaccinated children. The gene discussed is CD40LG; the disease is measles.