Assessment of Human Immune Responses to H7 Avian
Influenza Virus of Pandemic Potential: Results from a
Placebo–Controlled, Randomized Double–Blind Phase I
Study of Live Attenuated H7N3 Influenza Vaccine
Larisa Rudenko1, Irina Kiseleva1*, Anatoly N. Naykhin1, Marianna Erofeeva2, Marina Stukova3,
Svetlana Donina1, Galina Petukhova1, Maria Pisareva3, Vera Krivitskaya4, Michael Grudinin3,
Zhanna Buzitskaya3, Irina Isakova–Sivak1, Svetlana Kuznetsova1, Natalie Larionova1, Julia Desheva1,
Irina Dubrovina1, Alexandra Nikiforova5, John C. Victor6, Kathy Neuzil6, Jorge Flores6,
Vadim Tsvetnitsky6, Oleg Kiselev3
1 Department of Virology, Institute of Experimental Medicine, Saint Petersburg, Russia, 2 Department of Epidemiology and Prophylaxis, Institute of Influenza, Saint
Petersburg, Russia, 3 Department of Molecular Virology, Institute of Influenza, Saint Petersburg, Russia, 4 Department of Biotechnology, Institute of Influenza, Saint
Petersburg, Russia, 5 Department of Preclinical Trials, Microgen, Moscow, Russia, 6 Program for Appropriate Technologies in Health, Seattle, Washington, United States of
Introduction: Live attenuated influenza vaccines (LAIVs) are being developed to protect humans against future epidemics
and pandemics. This study describes the results of a double–blinded randomized placebo–controlled phase I clinical trial of
cold–adapted and temperature sensitive H7N3 live attenuated influenza vaccine candidate in healthy seronegative adults.
Objective: The goal of the study was to evaluate the safety, tolerability, immunogenicity and potential shedding and
transmission of H7N3 LAIV against H7 avian influenza virus of pandemic potential.
Methods and Findings: Two doses of H7N3 LAIV or placebo were administered to 40 randomly divided subjects (30
received vaccine and 10 placebo). The presence of influenza A virus RNA in nasal swabs was detected in 60.0% and 51.7% of
subjects after the first and second vaccination,...