Are there alternative avian influenza viruses for generation of stable attenuated avian-human influenza A reassortant viruses?
The present study evaluated gull influenza A viruses as donors of attenuating genes for the production of live, attenuated influenza A H1N1 and H3N2 avian-human (ah) reassortant viruses for use as vaccines to prevent disease due to influenza A viruses in humans. The previously evaluated duck influenza A viruses were abandoned as donors of attenuating avian influenza virus genes because clinical evaluation of H1N1 and H3N2 ah reassortant virus vaccines derived from duck viruses documented residual virulence of H1N1 reassortants for seronegative infants and young children. Gull influenza A viruses occupy an independent ecologic niche and are rarely isolated from species other than gulls. The possibility of using gull influenza A viruses as donors of internal gene segments in ah reassortant viruses was evaluated in the present study using three different gull viruses and three human influenza A viruses. Gull-human H3N2 reassortant influenza A viruses with the desired 6-2 genotype (six int
