Immunological basis of M13 phage vaccine: Regulation under MyD88 and TLR9 signaling

► Anti-phage IgG response was induced by a single administration of M13 phage without an adjuvant in mice. ► IgG response against M13 phage is completely dependent on MyD88 signaling. ► IgG1 production in primary response against M13 phage was elevated in TLR9-deficient mice.