CD4 and anthrax infection: In contrast, homologous prime-boost vaccination with rLVS ΔcapB/Ba and heterologous prime-boost vaccination with rLVS ΔcapB/Ba – rLm/Ba expressing an LFnPAc fusion protein, which gave strong protection against B. anthracis respiratory challenge, not only induced PA- and LF-specific serum IgG, dominated by Th1-type IgG2a, and toxin neutralizing antibody, but also induced strong T-cell responses, including IFNγ-, TNFα-, and/or IL2-expressing multifunctional CD4+ T cells, suggesting a role for T-cell mediated immunity in addition to humoral immunity in protection against anthrax.