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Paper of the Month April 2013

Boost Interval Matters: A Randomized Phase I Study to Identify the Minimum Interval to Observe the H5DNA Influenza Vaccine Priming Effect

J Infect Dis. 2013 Apr 30. [Epub ahead of print]


Ledgerwood JE, Zephir K, Hu Z, Wei CJ, Chang L, Enama ME, Hendel CS, Sitar S, Bailer RT, Koup RA, Mascola JR, Nabel GJ, Graham BS; the VRC 310 Study Team.



H5DNA priming was previously shown to improve antibody response to H5N1 monovalent inactivated vaccine (MIV) with a 24-week interval. This study defines the shortest prime-boost interval with improved response.


We administered H5DNA followed 4, 8, 12, 16, or 24 weeks by MIV as compared to two doses of MIV (24-week).


H5DNA priming with ≥12 week MIV boost showed improved response, with positive HAI in 91% [geometric mean titer (GMT) 141-206]; compared to ≤8-week boost (55-70%; GMT 51-70) or MIV-MIV 24-week boost (44% ; GMT 27).


H5DNA priming enhances antibody responses after an MIV boost when the interval is 12-24 weeks