Giuseppe
Emeritus
J Virol. 2009 May 20. [Epub ahead of print]
Evaluation of vaccines for H5N1 influenza virus in ferrets reveals the potential for protective single-shot immunisation.
Middleton D, Rockman S, Pearse M, Barr I, Lowther S, Klippel J, Ryan D, Brown L. Australian Animal Health Laboratory, Geelong, Victoria, Australia; CSL Limited, Parkville, Victoria, Australia; WHO Collaborating Centre for Influenza Reference and Research, Parkville, Victoria, Australia; and Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia.
As part of influenza pandemic preparedness, policy decisions need to be made about how best to utilise vaccines once they are manufactured. As H5N1 avian influenza virus has the potential to initiate the next human pandemic, isolates of this subtype have been used for the production and testing of pre-pandemic vaccines.
Clinical trials of such vaccines indicate that two injections of preparations containing adjuvant will be required to induce protective immunity. However, this is a working assumption based on classical serological measures only.
Examined here are the dose of viral hemagglutinin (HA) and the number of inoculations required for two different H5N1 vaccines to achieve protection in ferrets following lethal H5N1 challenge. Ferrets inoculated twice with 30microg A/Vietnam/1194/2004 HA vaccine with AlPO4,or doses as low as 3.8microg of HA with ISCOMATRIX(TM) adjuvant, were completely protected against death and disease following H5N1 challenge and protection lasted at least 15 mths.
Cross-clade protection was also observed with both vaccines. Significantly, complete protection against death could be achieved with only a single inoculation of H5N1 vaccine containing as little as 15microg HA with AlPO4 or 3.8microg HA with ISCOMATRIX(TM) adjuvant.
Ferrets vaccinated with the single-injection ISCOMATRIX(TM) vaccines showed fewer clinical manifestations of infection than those given AlPO4 vaccines and remained highly active. Our data provide the first indication that in the event of a future influenza pandemic, effective mass vaccination may be achievable with a low dose "single-shot" vaccine and provide not only increased survival but also significant reduction in disease severity.
PMID: 19457991 [PubMed - as supplied by publisher]
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Evaluation of vaccines for H5N1 influenza virus in ferrets reveals the potential for protective single-shot immunisation.
Middleton D, Rockman S, Pearse M, Barr I, Lowther S, Klippel J, Ryan D, Brown L. Australian Animal Health Laboratory, Geelong, Victoria, Australia; CSL Limited, Parkville, Victoria, Australia; WHO Collaborating Centre for Influenza Reference and Research, Parkville, Victoria, Australia; and Department of Microbiology and Immunology, The University of Melbourne, Parkville, Victoria, Australia.
As part of influenza pandemic preparedness, policy decisions need to be made about how best to utilise vaccines once they are manufactured. As H5N1 avian influenza virus has the potential to initiate the next human pandemic, isolates of this subtype have been used for the production and testing of pre-pandemic vaccines.
Clinical trials of such vaccines indicate that two injections of preparations containing adjuvant will be required to induce protective immunity. However, this is a working assumption based on classical serological measures only.
Examined here are the dose of viral hemagglutinin (HA) and the number of inoculations required for two different H5N1 vaccines to achieve protection in ferrets following lethal H5N1 challenge. Ferrets inoculated twice with 30microg A/Vietnam/1194/2004 HA vaccine with AlPO4,or doses as low as 3.8microg of HA with ISCOMATRIX(TM) adjuvant, were completely protected against death and disease following H5N1 challenge and protection lasted at least 15 mths.
Cross-clade protection was also observed with both vaccines. Significantly, complete protection against death could be achieved with only a single inoculation of H5N1 vaccine containing as little as 15microg HA with AlPO4 or 3.8microg HA with ISCOMATRIX(TM) adjuvant.
Ferrets vaccinated with the single-injection ISCOMATRIX(TM) vaccines showed fewer clinical manifestations of infection than those given AlPO4 vaccines and remained highly active. Our data provide the first indication that in the event of a future influenza pandemic, effective mass vaccination may be achievable with a low dose "single-shot" vaccine and provide not only increased survival but also significant reduction in disease severity.
PMID: 19457991 [PubMed - as supplied by publisher]
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