This result indicated that the role of specific SIgA in protecting against respiratory infection of Y. pestis needs to be further investigated, such as evaluating the survival rate of mice challenged with Y. pestis that had been preincubated with SIgA (70), or evaluating the efficacy of subunit vaccines via i.t. delivery in wild-type (WT) and IgA-deficient (IgA (-/-)) mice (71). The gene discussed is CD79A; the disease is respiratory tract infectious disorder.