• Kim JH, Talbot HK, Mishina M, Zhu Y, Chen J, Cao W, Reber AJ, Griffin MR, Shay DK, Spencer SM, Sambhara S. High-dose influenza vaccine favors acute plasmablast responses rather than long-term cellular responses. Vaccine. 2016 Aug 31;34(38). 4594-601. PMID: 27473306 [PubMed]. PMCID: PMC4996724. NIHMSID: NIHMS807258.

Abstract 

High-dose (HD) influenza vaccine shows improved relative efficacy against influenza disease compared to standard-dose (SD) vaccine in individuals ⩾65years. This has been partially credited to superior serological responses, but a comprehensive understanding of cell-mediated immunity (CMI) of HD vaccine remains lacking. In the current study, a total of 105 participants were randomly administered HD or SD vaccine and were evaluated for serological responses. Subsets of the group (n=12-26 per group) were evaluated for B and T cell responses at days 0, 7, 14 and 28 post-vaccination by flow cytometry or ELISPOT assay. HD vaccine elicited significantly higher hemagglutination inhibition (HI) titers than SD vaccine at d28, but comparable titers at d365 post-vaccination. HD vaccine also elicited higher vaccine-specific plasmablast responses at d7 post-vaccination than SD vaccine. However, long-lived memory B cell induction, cytokine-secreting T cell responses and persistence of serological memory were comparable regardless of vaccine dose. More strategies other than increased Ag amount may be needed to improve CMI in older adults.