The safety and immunogenicity of a MF59-adjuvanted H5N1 prepandemic influenza vaccine in healthy adults primed with homologous or heterologous H5N1 vaccines: an observational study.
BACKGROUND
World Health Organization (WHO) has recommended individuals with increased risk of contracting influenza A H5N1 infection to be immunized against the virus during the inter-pandemic period. Safety and immunogenicity of H5N1 vaccine among participants primed with homologous or heterologous H5N1 vaccines produced by diverse manufactures have not been reported.


METHODS
Healthy individuals aged 20 to 60 years old were recruited and stratified into three groups: participants without priming (control group), participants primed with A/Indonesia/05/2005 vaccine, participants primed with A/Vietnam/1194/2004 vaccine and A/Indonesia/05/2005 vaccine. Enrolled participants received two doses of MF59-adjuvanted A/Vietnam/1194/2004 vaccine (study vaccine). Solicited reactions were recorded by vaccine recipients. Blood samples were obtained for hemagglutination inhibition test.


RESULTS
A total of 131 participants were enrolled. No significant adverse events were recorded. Tenderness, fatigue and general muscle ache were the most common solicited reactions which alleviated within one week of immunization. Three weeks after two doses of the study vaccine, 63%, 68% and 88% were in seroprotective status in the control group, A/Indonesia/05/2005 primed group and A/Vietnam/1194/2004 and A/Indonesia/05/2005 primed group, respectively. Participants primed with A/Vietnam/1194/2004 and A/Indonesia/05/2005 showed high immune response after booster with one dose of the study vaccine.


CONCLUSIONS
The study vaccine did not cause severe adverse events. It elicited mostly mild to moderate reactions among participants. Participants primed with A/Vietnam/1194/2004 and A/Indonesia/05/2005 vaccine showed higher immune response than those without priming or primed with A/Indonesia/05/2005 vaccine. The report suggested those with an increased risk of influenza A H5N1 virus exposure may benefit from receiving influenza A H5N1 priming during the inter-pandemic period if the antigenicity of the pandemic influenza strain is similar to that of the priming strain.
Community Medicine Research Center and Institute of Public Health, National Yang-Ming University, No 155, Sec 2, Linong St., Beitou Dist, Taipei City, 112, Taiwan. epediat@gmail.com.|Centers for Disease Control, No.6, Linsen S Rd, Zhongzheng Dist, Taipei City, 10050, Taiwan. epediat@gmail.com.
Sung-Hsi
SH
Wei
Centers for Disease Control, No.6, Linsen S Rd, Zhongzheng Dist, Taipei City, 10050, Taiwan. mtliu@cdc.gov.tw.
Ming-Tsan
MT
Liu
Department of Internal Medicine, Changhua Hospital, Ministry of Health and Welfare, No 80, Sec 2, Zhongzheng Rd, Puxin Township, Changhua County, 513, Taiwan. jacktsai1998@gmail.com.
Yao-Chou
YC
Tsai
Department of Internal Medicine, Changhua Hospital, Ministry of Health and Welfare, No 80, Sec 2, Zhongzheng Rd, Puxin Township, Changhua County, 513, Taiwan. pytkgb@yahoo.com.tw.
Chung-Hsin
CH
Liao
Department of Internal Medicine, Tungs' Taichung MetroHarbor Hospital, No 699, Sec 8, Taiwan Blvd, Wuqi Dist, Taichung City, 435, Taiwan. chioming2002@yahoo.com.tw.
Chih-Ming
CM
Chen
Department of Internal Medicine, Feng Yuan Hospital, Ministry of Health and Welfare, No.100, Ankang Rd., Fengyuan Dist, Taichung City, 420, Taiwan. wywang1966@ndmctsgh.edu.tw.
Wei-Yao
WY
Wang
Centers for Disease Control, No.6, Linsen S Rd, Zhongzheng Dist, Taipei City, 10050, Taiwan. flutedreams@hotmail.com.
Yi-Lung
YL
Huang
Centers for Disease Control, No.6, Linsen S Rd, Zhongzheng Dist, Taipei City, 10050, Taiwan. fychang@ndmctsgh.edu.tw.|Division of Infectious Diseases and Tropical Medicine, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Cheng-Kung Rd, Neihu, Taipei City, 114, Taiwan. fychang@ndmctsgh.edu.tw.
Feng-Yee
FY
Chang
Community Medicine Research Center and Institute of Public Health, National Yang-Ming University, No 155, Sec 2, Linong St., Beitou Dist, Taipei City, 112, Taiwan. pschou@ym.edu.tw.
Pesus
P
Chou
D000276:Adjuvants, Immunologic / Q000627:therapeutic use*; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D000917:Antibody Formation; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007117:Immunization, Secondary; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology / Q000627:therapeutic use*; D007251:Influenza, Human / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D058873:Pandemics; D011136:Polysorbates / Q000627:therapeutic use*; D013185:Squalene / Q000276:immunology / Q000627:therapeutic use*; D014611:Vaccination; D014744:Vietnam; D014944:World Health Organization; D055815:Young Adult
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines; C089950:MF59 oil emulsion; D011136:Polysorbates; D013185:Squalene