BACKGROUND: In 1999, avian influenza A/Hong Kong/1073/99 (H9N2) virus emerged as a pandemic threat to human beings. We aimed to assess safety, tolerability, and antigenicity of whole virus and subunit H9N2 vaccines in healthy volunteers. METHODS: In a phase I randomised trial we randomly assigned 60 participants to whole virus or subunit H9N2 vaccine. Two doses of 7.5 microg, 15 microg, or 30 microg haemagglutinin influenza A H9N2 vaccine, were given 3 weeks apart. We measured antibody responses by haemagglutination-inhibition and microneutralisation. The primary outcome was geometric mean antibody titre 21 days after vaccination. Analysis was per protocol. FINDINGS: Both vaccines were safe and well tolerated. The antibody titres after vaccination did not differ significantly between subunit and whole virus vaccine. 24 of 60 prevaccination serum samples had unexpected reactivity to H9N2, but only in participants older than 32 years, in whom one dose of either vaccine evoked antibody responses associated with protection. In participants aged 32 years or younger, antibody responses to one dose of whole virus or subunit vaccine were poor, fulfilling none of the criteria used for yearly relicensing of interpandemic vaccines. Whole virus vaccine produced a significantly higher probability of seroconversion compared with subunit virus for this age-group. INTERPRETATION: In immunologically naive patients whole-virus vaccine produced better responses than subunit vaccine. Two doses of subunit or whole virus vaccine would leave a large proportion of the naive population (< or =32 years) unprotected against A/Hong Kong/1073/99 (H9N2). Primed patients should be protected with a single dose of either vaccine.
RCT Entities:
BACKGROUND: In 1999, avian influenza A/Hong Kong/1073/99 (H9N2) virus emerged as a pandemic threat to human beings. We aimed to assess safety, tolerability, and antigenicity of whole virus and subunit H9N2 vaccines in healthy volunteers. METHODS: In a phase I randomised trial we randomly assigned 60 participants to whole virus or subunit H9N2 vaccine. Two doses of 7.5 microg, 15 microg, or 30 microg haemagglutinin influenza A H9N2 vaccine, were given 3 weeks apart. We measured antibody responses by haemagglutination-inhibition and microneutralisation. The primary outcome was geometric mean antibody titre 21 days after vaccination. Analysis was per protocol. FINDINGS: Both vaccines were safe and well tolerated. The antibody titres after vaccination did not differ significantly between subunit and whole virus vaccine. 24 of 60 prevaccination serum samples had unexpected reactivity to H9N2, but only in participants older than 32 years, in whom one dose of either vaccine evoked antibody responses associated with protection. In participants aged 32 years or younger, antibody responses to one dose of whole virus or subunit vaccine were poor, fulfilling none of the criteria used for yearly relicensing of interpandemic vaccines. Whole virus vaccine produced a significantly higher probability of seroconversion compared with subunit virus for this age-group. INTERPRETATION: In immunologically naive patients whole-virus vaccine produced better responses than subunit vaccine. Two doses of subunit or whole virus vaccine would leave a large proportion of the naive population (< or =32 years) unprotected against A/Hong Kong/1073/99 (H9N2). Primed patients should be protected with a single dose of either vaccine.
Authors: Jae-Min Song; Jaber Hossain; Dae-Goon Yoo; Aleksandr S Lipatov; C Todd Davis; Fu-Shi Quan; Li-Mei Chen; Robert J Hogan; Ruben O Donis; Richard W Compans; Sang-Moo Kang Journal: Virology Date: 2010-06-26 Impact factor: 3.616
Authors: Joshua M DiNapoli; Lijuan Yang; Amorsolo Suguitan; Subbiah Elankumaran; David W Dorward; Brian R Murphy; Siba K Samal; Peter L Collins; Alexander Bukreyev Journal: J Virol Date: 2007-08-22 Impact factor: 5.103
Authors: Patrick J Blair; Shannon D Putnam; Whitney S Krueger; Channimol Chum; Thomas F Wierzba; Gary L Heil; Chadwick Y Yasuda; Maya Williams; Matthew R Kasper; John A Friary; Ana W Capuano; Vonthanak Saphonn; Malik Peiris; Hongxia Shao; Daniel R Perez; Gregory C Gray Journal: J Infect Public Health Date: 2013-02-01 Impact factor: 3.718
Authors: Arnt-Ove Hovden; Karl A Brokstad; Diane Major; John Wood; Lars R Haaheim; Rebecca J Cox Journal: Influenza Other Respir Viruses Date: 2009-01 Impact factor: 4.380
Authors: Jean-Michel Garcia; Stephanie Pepin; Nadège Lagarde; Edward S K Ma; Frederick R Vogel; Kwok H Chan; Susan S S Chiu; J S M Peiris Journal: PLoS One Date: 2009-11-20 Impact factor: 3.240