Live Attenuated Reassortant Vaccines Based on A/Leningrad/134/17/57 Master Donor Virus Against H5 Avian Influenza.

Background: The H5N1 avian influenza was first recognized in humans in Hong Kong 20 years ago. Current enzootic spread of highly pathogenic H5N1 virus among wild and domestic poultry and a number of severe human respiratory diseases caused by this pathogen have stimulated necessity of development of potentially pandemic influenza vaccines.

Discussion: In the past few years, significant research was conducted on how to prevent H5N1 influenza. Live, attenuated cold-adapted reassortant influenza vaccine (LAIV) is considered as one of the most promising candidates for pandemic and prepandemic vaccines. LAIV has proven to be safe and efficacious; pandemic LAIV might be more effective than inactivated vaccine in providing broader immune response.

Conclusion: This review covers development of LAIVs against potential avian "pandemic" H5N1 subtype based on cold-adapted A/Leningrad/134/17/57 (H2N2) master donor virus backbone, and their preclinical and clinical studies.