TY - JOUR T1 - Recombinant influenza A virus vaccines for the pathogenic human A/Hong Kong/97 (H5N1) viruses. AU - Li,S, AU - Liu,C, AU - Klimov,A, AU - Subbarao,K, AU - Perdue,M L, AU - Mo,D, AU - Ji,Y, AU - Woods,L, AU - Hietala,S, AU - Bryant,M, PY - 1999/4/7/pubmed PY - 2000/3/21/medline PY - 1999/4/7/entrez SP - 1132 EP - 8 JF - The Journal of infectious diseases JO - J Infect Dis VL - 179 IS - 5 N2 - Recombinant reassortment technology was used to prepare H5N1 influenza vaccine strains containing a modified hemagglutinin (HA) gene and neuraminidase gene from the A/Hong Kong/156/97 and A/Hong Kong/483/97 isolates and the internal genes from the attenuated cold-adapted A/Ann Arbor/6/60 influenza virus strain. The HA cleavage site (HA1/HA2) of each H5N1 isolate was modified to resemble that of "low-pathogenic" avian strains. Five of 6 basic amino acids at the cleavage site were deleted, and a threonine was added upstream of the remaining arginine. The H5 HA cleavage site modification resulted in the expected trypsin-dependent phenotype without altering the antigenic character of the H5 HA molecule. The temperature-sensitive and cold-adapted phenotype of the attenuated parent virus was maintained in the recombinant strains, and they grew to 108.5-9.4 EID50/mL in eggs. Both H5N1 vaccine virus strains were safe and immunogenic in ferrets and protected chickens against wild-type H5N1 virus challenge. SN - 0022-1899 UR - https://www.unboundmedicine.com/medline/citation/10191214/Recombinant_influenza_A_virus_vaccines_for_the_pathogenic_human_A/Hong_Kong/97__H5N1__viruses_ L2 - https://academic.oup.com/jid/article-lookup/doi/10.1086/314713 DB - PRIME DP - Unbound Medicine ER -