Irina Kiseleva, Natalie Larionova, Ekaterina Fedorova, Irina Isakova-Sivak, Larisa Rudenko
Avian influenza viruses remain a major pandemic threat. In response to this threat, a number of pandemic vaccines have been developed. The objective of this paper is to review and summarize data from preclinical and clinical evaluation of Russian live attenuated influenza vaccines (LAIVs) against pandemic influenza based on cold-adapted A/Leningrad/134/17/57 (H2N2) master donor virus (MDV). The described LAIVs consist of reassortant viruses of 6:2 and 7:1 genomic composition (6 MDV genes: 2 WT genes and 7 MDV genes: 1 WT gene, respectively). Despite the differences in their genomic composition (6:2 or 7:1), LAIV candidates of H5, H7 and H2 subtypes acquired temperature sensitivity, cold-adaptation, and attenuation for different animal models. In addition, they were safe and immunogenic for healthy adult volunteers. The collected data indicate that 7:1 reassortants carrying HA genes of potentially pandemic viruses and the remaining genes from the MDV might be preferable pandemic LAIV candidates.
