Peptide vaccination is superior to genetic vaccination using a recombineered bacteriophage λ subunit vaccine

► For the first time a direct comparison of a genetic immunization and a peptide immunization was undertaken using the same vector. ► When IL-2, IL-4 and IFNγ are measured in immunized mice, peptides displayed on bacteriophage lambda are superior at eliciting an immune response, as compared to genetic immunization. ► Antibodies from peptide vaccinated animals bind epitopes across a broader pH than animals with a genetic immunization. In fact genetic immunization did not produce antibodies that bound epitopes at physiological pH. ► The immune response to bacteriophage lambda is Th1 dominated as determined by the expression of IFNγ by splenocytes, and the concentration of IgG2a antibodies. ► A bacteriophage recombination method was developed to engineer displayed proteins or peptides on bacteriophage lambda capsids. This is the first example of recombineering for a bacteriophage lambda display vector.