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Editor, Senior Moderator
Superior antigen-specific CD4+ T-cell response with AS03-adjuvantation of a trivalent influenza vaccine in a randomised trial of adults aged 65 and older
Robert B Couch, Jos? M Bayas, Covadonga Caso, Innocent Nnadi Mbawuike, Concepci?n N??ez L?pez, Carine Claeys, Mohamed El Idrissi, Caroline Herv?, B?atrice Laup?ze, Lidia Oostvogels and Philippe Moris
Author Affiliations
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BMC Infectious Diseases 2014, 14:425 doi:10.1186/1471-2334-14-425
Published: 30 July 2014
Abstract (provisional)
Background
The effectiveness of trivalent influenza vaccines may be reduced in older versus younger adults because of age-related immunosenescence. The use of an adjuvant in such a vaccine is one strategy that may combat immunosenescence, potentially by bolstering T-cell mediated responses.
Methods
This observer-blind study, conducted in the United States (US) and Spain during the 2008-2009 influenza season, evaluated the effect of Adjuvant System AS03 on specific T-cell responses to a seasonal trivalent influenza vaccine (TIV) in >=65 year-old adults.
Medically-stable adults aged >=65 years were randomly allocated to receive a single dose of AS03-adjuvanted TIV (TIV/AS03) or TIV. Healthy adults aged 18-40 years received only TIV. Blood samples were collected on Day 0, Day 21, Day 42 and Day 180. Influenza-specific CD4+ T cells, defined by the induction of the immune markers CD40L, IL-2, IFN-gamma, or TNF-alpha, were measured in ex vivo cultures of antigen-stimulated peripheral blood mononuclear cells.
Results
A total of 192 adults were vaccinated: sixty nine and seventy three >=65 year olds received TIV/AS03 and TIV, respectively; and fifty 18 - 40 year olds received TIV. In the >=65 year-old group on Day 21, the frequency of CD4+ T cells specific to the three vaccine strains was superior in the TIV/AS03 recipients to the frequency in TIV (p < 0.001). On Days 42 and 180, the adjusted-geometric mean specific CD4+ T-cell frequencies were also higher in the TIV/AS03 recipients than in the TIV recipients (p < 0.001). Furthermore, the adjusted-geometric mean specific CD4+ T-cell frequencies were higher in the >=65 year-old recipients of TIV/AS03 than in the18 - 40 year old recipients of TIV on Days 21 (p = 0.006) and 42 (p = 0.011).
Conclusion
This positive effect of AS03 Adjuvant System on the CD4+ T-cell response to influenza vaccine strains in older adults could confer benefit in protection against clinical influenza disease in this population.
full article
http://www.biomedcentral.com/content/pdf/1471-2334-14-425.pdf
Robert B Couch, Jos? M Bayas, Covadonga Caso, Innocent Nnadi Mbawuike, Concepci?n N??ez L?pez, Carine Claeys, Mohamed El Idrissi, Caroline Herv?, B?atrice Laup?ze, Lidia Oostvogels and Philippe Moris
Author Affiliations
For all author emails, please log on.
BMC Infectious Diseases 2014, 14:425 doi:10.1186/1471-2334-14-425
Published: 30 July 2014
Abstract (provisional)
Background
The effectiveness of trivalent influenza vaccines may be reduced in older versus younger adults because of age-related immunosenescence. The use of an adjuvant in such a vaccine is one strategy that may combat immunosenescence, potentially by bolstering T-cell mediated responses.
Methods
This observer-blind study, conducted in the United States (US) and Spain during the 2008-2009 influenza season, evaluated the effect of Adjuvant System AS03 on specific T-cell responses to a seasonal trivalent influenza vaccine (TIV) in >=65 year-old adults.
Medically-stable adults aged >=65 years were randomly allocated to receive a single dose of AS03-adjuvanted TIV (TIV/AS03) or TIV. Healthy adults aged 18-40 years received only TIV. Blood samples were collected on Day 0, Day 21, Day 42 and Day 180. Influenza-specific CD4+ T cells, defined by the induction of the immune markers CD40L, IL-2, IFN-gamma, or TNF-alpha, were measured in ex vivo cultures of antigen-stimulated peripheral blood mononuclear cells.
Results
A total of 192 adults were vaccinated: sixty nine and seventy three >=65 year olds received TIV/AS03 and TIV, respectively; and fifty 18 - 40 year olds received TIV. In the >=65 year-old group on Day 21, the frequency of CD4+ T cells specific to the three vaccine strains was superior in the TIV/AS03 recipients to the frequency in TIV (p < 0.001). On Days 42 and 180, the adjusted-geometric mean specific CD4+ T-cell frequencies were also higher in the TIV/AS03 recipients than in the TIV recipients (p < 0.001). Furthermore, the adjusted-geometric mean specific CD4+ T-cell frequencies were higher in the >=65 year-old recipients of TIV/AS03 than in the18 - 40 year old recipients of TIV on Days 21 (p = 0.006) and 42 (p = 0.011).
Conclusion
This positive effect of AS03 Adjuvant System on the CD4+ T-cell response to influenza vaccine strains in older adults could confer benefit in protection against clinical influenza disease in this population.
full article
http://www.biomedcentral.com/content/pdf/1471-2334-14-425.pdf