Temperature-Sensitive Mutants of Influenza A Virus: Production and Characterization of A/Victoria/3/75- ts -1[E] Recombinants

Abstract

The Hong Kong/68-ts-l[E] virus, which has a 380C shutoff temperature for plaque formation, has been proposed as a donor of its two ts lesions to new variants of influenza A virus that pose an epidemic threat. To further examine whether the acquisition of the two ts-l[E] lesions will predictably attenuate new influenza A variants, the HK/68-ts-1[E] virus was mated with the A/Vic/3/75 wild-type virus. The Vic/75-ts-[E] recombinants that had the two ts-l[E] lesions also had a 380C shutoff temperature. Two Vic/75-ts-l[E] recombinants (clones 81 and 113) that had the two ts-l[E] lesions, a 380C shutoff temperature, and the

Temperature-Sensitive Mutants of Influenza A Virus: Evaluation of A/Victoria/3/75- ts -1[E] Recombinant Viruses in Volunteers

“…MATERIALS AND METHODS Viruses. The wild-type A/Victoria/3/75 virus was isolated in specific pathogen-free eggs as described (9). The wild-type virus suspension administered to volunteers was uncloned and had undergone two passages in specific pathogen-free eggs.…”

“…The wild-type virus suspension administered to volunteers was uncloned and had undergone two passages in specific pathogen-free eggs. The production and characterization of the A/Vic/3/75-ts-1[E] recombinant clones 81 and 113 were described previously (9). Briefly, they were recombinants that: (i) had a 380C shutoff temperature of plaque formation like their HK/68-ts-1[E] parent; (ii) possessed the hemagglutinin and neuraminidase of the Vic/75 wild-type virus; and (iii) had the two ts genes of the HK/68-ts-1[E]…”

Temperature-sensitive mutants of influenza A virus: evaluation of the A/Victoria/75-ts-1A2 temperature-sensitive recombinant virus in seronegative adult volunteers

“…MATERIALS AND METHODS Viruses. The production of the A/Vic/75-ts-lA2 (H3N2) virus, clone 76, was described previously (5).…”

“…The production and characterization of the A/Vic/75-ts-l[E] recombinant (clone 81) and A/Vic/75 wild-type virus have been described previously (5). The data obtained from volunteers who received the A/Vic/75-ts-l[E] virus were described previously and are included here for purposes of comparison (6).…”

Live influenza A/Victoria/75 (H3N2) virus vaccines: reactogenicity, immunogenicity, and protection against wild-type virus challenge

“…Wild-type influenza A/Victoria/3/75 (H3N2) virus was isolated and grown in specific pathogen-free eggs (14). Production and characterization of the A/ Victoria/75-ts-1[E] recombinant clone 81 (14), the A/ Victoria/75-ts-lA2 recombinant clone 76 (17), and the CR19 (8) and CR22 clone 2 (18) recombinants of A/ Victoria/75 with cold-adapted A/Ann Arbor/6/60 (H2N2) have been described. Each of the recombinant virus vaccine candidates possessed A/Victoria/75 (H3N2) surface antigens and was finally grown in specific pathogen-free eggs.…”