The results of our studies with the Tlr2, 4, and 2/4 double deficient or adaptor protein Myd88 deficient mice suggest that Tlr4 and MyD88 appear to be important for an optimal antibody response to the subunit F1-V plague vaccine, but MyD88 also appears to be required for protection against a lethal Y. pestis CO92 challenge in F1-V vaccinated mice. The gene discussed is TLR4; the disease is plague.