IgA local immune response persists for a period of 3‐5 months5, 12, 13 and then gradually diminishes returning to the pre‐immunization levels within 6 months.14 In addition, it is possible to detect IgA‐producing memory cells locally.5, 12, 13 CTLs appear transiently in the nasal mucosa and peak on day 7 after infection. The gene discussed is CD79A; the disease is infection.