Are you Gary Ong?

Claim your profile

Publications (4)1.63 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A multicenter study (NCT00449670) conducted across Taiwan, Singapore, Hong Kong and Thailand evaluated the safety and manufacturing consistency of four formulations of an AS03(A)-adjuvanted H5N1 vaccine in terms of immune response against the vaccine-homologous strain (A/Vietnam/1194/2004). This manuscript presents data from the Taiwanese population. A total of 400 individuals, aged 18-60 years, were randomized into six groups (2:2:2:2:1:1 ratio) to receive two doses (21 days apart) of one of the four adjuvanted formulations (H5N1-AS03(A)-groups) or one of the two nonadjuvanted formulations (H5N1-DIL-groups). Blood samples collected before vaccination (Day 0) and 21 days after each vaccine dose were analyzed using hemagglutination inhibition (HI) assay. Adverse events were recorded. All four AS03(A)-adjuvanted formulations induced comparable immune responses against the A/Vietnam/1194/2004 strain; following the second dose, immune response in terms of HI antibodies was higher in the H5N1-AS03(A)-groups {seroprotection rate=91.6% [95% confidence interval (CI): 87.9-94.4]; geometric mean titer (GMT)=177.6 (95% CI: 153.2-206.0)} compared with the H5N1-DIL-groups [seroprotection rates=5.0% (95% CI: 1.4-12.3); GMT=6.3 (95% CI: 5.4-7.4)]. Immune response against the heterologous A/Indonesia/05/2005 strain was also stronger in the H5N1-AS03(A)-groups [seroprotection rate=45.6% (95% CI: 40.0-51.4); GMT=20.5 (95% CI: 17.8-23.7)] compared with the H5N1-DIL groups [seroprotection rate=0.0% (95% CI: 0.0-4.5); GMT=5.0 (95% CI: 5.0-5.0)]. The overall reactogenicity profile of the adjuvanted formulations was clinically acceptable. The AS03(A)-adjuvanted H5N1 influenza vaccine formulations induced stronger immune response against the vaccine-homologous and heterologous strains than the nonadjuvanted formulations. The AS03(A)-adjuvanted H5N1 vaccine demonstrated a good immunogenicity and an acceptable safety profile in the Taiwanese population.
    Journal of the Formosan Medical Association 12/2011; 110(12):780-6. · 1.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The present study (NCT00449670) in Asian subjects (18-60 years) evaluated the manufacturing consistency of four formulations of 3.75 mg AS03(A)-adjuvanted H5N1 influenza vaccine, in terms of post-immunization Hemagglutination Inhibition (HI) titers against the A/Vietnam/1194/2004 and A/Indonesia/05/2005 strains. The immunogenicity and safety of the vaccine in the Thai population are reported herein. Subjects were randomized (2:2:2:2.:1:1) between four vaccine groups and two control groups to receive two doses of either the AS03(A)-adjuvanted or non-adjuvanted H5N1 vaccine formulations, 21 days apart. Sera were assayed for HI antibody titers against the two strains. After the second dose of AS03(A)-adjuvanted vaccine, 94.2% subjects in the H5N1-AS03(A) groups seroconverted and 94.9% subjects were seroprotected against the A/Vietnam/1194/2004 strain. Cross-clade immune response against the A/Indonesia/05/2005 strain was observed. All vaccine formulations had an acceptable safety profile. This antigen-sparing AS03(A)-adjuvanted influenza vaccine could be a suitable candidate for combating and mitigating future influenza pandemics.
    Journal of the Medical Association of Thailand = Chotmaihet thangphaet 08/2011; 94(8):916-26.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To present Hong Kong'Äìspecific data from a large Asian population (also involving Thailand, Singapore, and Taiwan) on safety and manufacturing consistency across four AS03(A)-adjuvanted H5N1 vaccine formulations in terms of immune response against the A/Vietnam/1194/2004 strain. Immunogenicity against the heterologous A/Indonesia/05/2005 strain was also assessed. NCT Number: 00449670. Prospective, observer-blind study. Out-patient clinic of a tertiary hospital in Hong Kong. A total of 360 subjects aged 18 to 60 years were randomised into six groups to receive two doses (21 days apart) of the study vaccine. One of the four adjuvanted formulations (3.75 microgram H5N1 haemagglutinin [HA]+AS03(A)) of the vaccine (H5N1-AS03(A)) or one of the two non-adjuvanted (3.75 microgram H5N1 [HA]) formulations of the vaccine (H5N1-DIL). Blood samples collected before vaccination and 21 days after each vaccine dose were analysed using haemagglutination-inhibition and neutralisation assays. Solicited, unsolicited, and serious adverse events were recorded. Manufacturing consistency across all four vaccine formulations was demonstrated. After two doses, the AS03(A)-adjuvanted prepandemic influenza vaccine demonstrated high seroprotection rates against the A/Vietnam/1194/2004 strain (95.8%) and good immunogenicity against the heterologous A/Indonesia/05/2005 strain (45.7%), as compared to the non-adjuvanted vaccine (4.6% and 1.5%, respectively). The seroconversion rates induced by the adjuvanted formulations in terms of viral neutralising antibodies against the two strains were much higher than those induced by the non-adjuvanted formulations. There were no safety concerns for any of the adjuvanted vaccine formulations. The AS03(A)-adjuvanted H5N1 prepandemic influenza vaccine demonstrated good immunogenicity and an acceptable safety profile in Hong Kong.
    Hong Kong medical journal = Xianggang yi xue za zhi / Hong Kong Academy of Medicine 02/2011; 17(1):39-46.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Seasonal influenza vaccination is recommended for diabetics; however, the vaccination uptake rate among diabetics remains low. This study explored the knowledge, attitudes and practices among diabetics in Singapore with regard to influenza and influenza vaccination. A survey was conducted among type 1 and 2 diabetes mellitus patients who attended three management centres of the Diabetic Society of Singapore in January 2007. The pilot-tested questionnaire covered influenza and influenza vaccination in terms of the patient demographics, medical history and knowledge, attitudes and practices. A total of 307 diabetics participated in the study. Of these, 139 (45.3 percent) claimed to know the difference between influenza and the common cold, while 98 (31.9 percent) and 18 (5.9 percent) participants thought that influenza vaccines protected against all influenza strains and provided lifelong immunity, respectively. 247 (80.4 percent) participants were aware that they were at a moderate or higher risk for influenza-related complications, while 181 (58.9 percent) considered vaccination to be effective in preventing influenza and its complications. Only 94 (30.6 percent) participants were previously vaccinated. Among those unvaccinated, 117 (54.9 percent) did not think vaccination was necessary, while 104 (48.8 percent) had never considered it. As observed from the multivariate analysis, income was a key predictor of influenza vaccination. While 241 (78.5 percent) participants cited healthcare professional advice as the main guiding factor for getting vaccinated, 199 (64.8 percent) had never been advised on influenza vaccination. Of the 108 (35.1 percent) participants who had received previous advice on influenza vaccination, the majority had received it from their healthcare professionals. Uptake of influenza vaccination among diabetics in Singapore is low, and the key predictor is income. Perception and knowledge are the main barriers, and hence, healthcare professionals should educate and encourage vaccination among diabetics.
    Singapore medical journal 08/2010; 51(8):623-30. · 0.63 Impact Factor