Safety and Immunogenicity of a Single Low Dose or High Dose of Clade 2 Influenza A(H5N1) Inactivated Vaccine in Adults Previously Primed With Clade 1 Influenza A(H5N1) Vaccine
Year of Publication
Winokur, PL; Patel, SM; Brady, R; Chen, WH; El-Kamary, SS; Edwards, K; Creech, CB; Frey, S; Keitel, WA; Belshe, R; Walter, E; Bellamy, A; Hill, H; The VTEU-H3Nv Vaccine Study Work Group
J Infect Dis
H5n1; influenza; prime-boost; vaccine
Influenza A(H5N1) vaccination strategies that improve the speed of the immunological response and cross-clade protection are desired. We compared the immunogenicity of a single 15-mug or 90-mug dose of A/H5N1/Indonesia/05/05 (clade 2) vaccine in adults who were previously primed with A/H5N1/Vietnam/1203/2004 (clade 1) vaccine. High-dose vaccine resulted in significantly higher titers to both clade 1 and 2 antigens. Clade 2 titers were unaffected by the previous dose of clade 1 vaccine. Low-dose priming with a mismatched pandemic influenza A(H5N1) vaccine would improve the rapidity, magnitude, and cross-reactivity of the immunological response following a single high-dose, unadjuvanted, pandemic vaccine.