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Safety and Immunogenicity of a Subvirion Monovalent Unadjuvanted Inactivated Influenza A(H3N2) Variant Vaccine in Healthy Persons ≥18 Years Old.

Authors :
Keitel, Wendy A
Jackson, Lisa A
Edupuganti, Srilatha
Winokur, Patricia L
Mulligan, Mark J
Thornburg, Natalie J
Patel, Shital M
Rouphael, Nadine G
Lai, Lilin
Bangaru, Sandhya
McNeal, Monica M
Bellamy, Abbie R
Hill, Heather R
VTEU H3N2v Vaccine Study Work Group
Source :
Journal of Infectious Diseases. 8/15/2015, Vol. 212 Issue 4, p552-561. 10p.
Publication Year :
2015

Abstract

<bold>Background: </bold>Variant influenza A(H3N2) viruses (H3N2v) have transmitted recently from pigs to humans in the United States. Vaccines strategies are needed.<bold>Methods: </bold>Healthy adults received 2 doses of subvirion H3N2v vaccine (15 µg of hemagglutinin/dose) 21 days apart in this open-label trial. Serum hemagglutination inhibition (HAI) and neutralizing (Neut) antibody (Ab) titers were measured before and 8 and 21 days after each dose. Memory B-cell (MBC) responses were assessed.<bold>Results: </bold>Vaccine was well tolerated. A total of 40% of subjects had an HAI Ab titer of ≥40 before vaccination. Eight-seven percent (95% confidence interval [CI], 79%-93%) and 73% (95% CI, 63%-81%) of subjects 18-64 years old (98 subjects) and ≥65 years old (90 subjects), respectively, had an HAI titer of ≥40 21 days after dose 1 (P = .01); 51% (95% CI, 41%-61%) and 52% (95% CI, 41%-62%) of younger and older subjects, respectively, developed ≥4-fold rises in titer (P = not significant). Neut Ab response patterns were similar. Geometric mean titers were higher in younger subjects. Dose 2 provided no significant enhancement in responses. Cross-reactive MBCs were detected before vaccination and expanded after vaccination. Preexisting H3N2v-specific MBCs positively correlated with early increases in vaccine-induced Ab.<bold>Conclusions: </bold>In most healthy adults, one 15-µg dose of vaccine elicited levels of HAI Abs associated with protection. Studies in children and elderly individuals are indicated to define the immunization needs of these groups.<bold>Clinical Trials Registration: </bold>NCT01746082. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00221899
Volume :
212
Issue :
4
Database :
Academic Search Index
Journal :
Journal of Infectious Diseases
Publication Type :
Academic Journal
Accession number :
109606196
Full Text :
https://doi.org/10.1093/infdis/jiv056