Antibody Persistence and Booster Responses to Split-Virion H5N1 Avian Influenza Vaccine in Young and Elderly Adults.
Avian influenza continues to circulate and remains a global health threat not least because of the associated high mortality. In this study antibody persistence, booster vaccine response and cross-clade immune response between two influenza A(H5N1) vaccines were compared. Participants aged over 18-years who had previously been immunized with a clade 1, A/Vietnam vaccine were re-immunized at 6-months with 7.5 μg of the homologous strain or at 22-months with a clade 2, alum-adjuvanted, A/Indonesia vaccine. Blood sampled at 6, 15 and 22-months after the primary course was used to assess antibody persistence. Antibody concentrations 6-months after primary immunisation with either A/Vietnam vaccine 30 μg alum-adjuvanted vaccine or 7.5 μg dose vaccine were lower than 21-days after the primary course and waned further with time. Re-immunization with the clade 2, 30 μg alum-adjuvanted vaccine confirmed cross-clade reactogenicity. Antibody cross-reactivity between A(H5N1) clades suggests that in principle a prime-boost vaccination strategy may provide both early protection at the start of a pandemic and improved antibody responses to specific vaccination once available.


BACKGROUND
ClinicalTrials.gov NCT00415129.
Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.
Rajeka
R
Lazarus
Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.
Sarah
S
Kelly
Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.
Matthew D
MD
Snape
Center for Environment and Health, Leuven University, Leuven, Belgium.|Vaccinology Center, Leuven University, Leuven, Belgium.
Corinne
C
Vandermeulen
Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom.
Merryn
M
Voysey
Center for Environment and Health, Leuven University, Leuven, Belgium.
Karel
K
Hoppenbrouwers
Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
Annick
A
Hens
Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
Pierre
P
Van Damme
Sanofi Pasteur, Marcy l'Etoile, France.
Stephanie
S
Pepin
Center for Vaccinology, Ghent University and Ghent University Hospital, Ghent, Belgium.
Isabel
I
Leroux-Roels
Center for Vaccinology, Ghent University and Ghent University Hospital, Ghent, Belgium.
Geert
G
Leroux-Roels
Oxford Vaccine Group, Department of Paediatrics, Centre for Clinical Vaccinology and Tropical Medicine, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom.
Andrew J
AJ
Pollard
D000276:Adjuvants, Immunologic / Q000008:administration & dosage; D000293:Adolescent; D000328:Adult; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D000917:Antibody Formation / Q000276:immunology; D001717:Birds / Q000276:immunology / Q000821:virology; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods; D007214:Indonesia; D053124:Influenza A Virus, H5N1 Subtype / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D005585:Influenza in Birds / Q000276:immunology* / Q000821:virology; D007251:Influenza, Human / Q000276:immunology* / Q000821:virology; D008297:Male; D008875:Middle Aged; D009500:Neutralization Tests / Q000379:methods; D014611:Vaccination / Q000379:methods; D014744:Vietnam; D014771:Virion / Q000276:immunology*; D055815:Young Adult
D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D007252:Influenza Vaccines