Background: Little is known about factors associated with maintenance of hemagglutinin inhibition (HAI) antibodies after influenza vaccination in older adults. Methods: Adults ≥50 years of age were vaccinated prior to the 2009-10 influenza season. Serum was drawn pre-vaccination (S1), 21-28 days post-vaccination (S2), and after the influenza season (S3) for HAI assays. Seroconversion was defined as ≥ 4-fold increase S1 to S2 (or if S1 < 10, by an S2 ≥ 40) and seroprotection was defined as S2 ≥ 40. Maintenance of antibody response was measured in participants with an S2 ≥ 40, and defined as an S3 ≥ 40. Results: We enrolled 510 participants during Fall 2009 at Vanderbilt University Medical Center and Marshfield Clinic Research Foundation. Participants' mean age was 64 years with 62% female and 96% white. Seroconversion and seroprotection rates were lowest for influenza A H1N1 (12% and 26%, respectively), highest for influenza A H3N2 (45% and 82%), and intermediate for influenza B (28% and 72%). Of the participants with an S2 ≥ 40, 36% (46/126), 71% (289/407), and 74% (263/354) maintained an S3 ≥ 40 for H1N1, H3N2, and B influenza vaccine strains, respectively. S1 HAI titer was strongly associated with both post-vaccination seroprotection and maintaining seroprotection at S3 for all three influenza antigens. Age, sex, body mass index, self-reported stress, and vaccination site were not consistently associated with vaccine response or maintenance of response. Conclusions: Pre-vaccination antibody titer was the only study variable consistently and positively associated with both serologic response to vaccination and maintenance of response. Antibody responses were lowest for the H1N1 vaccine strain. ClinicalTrials: gov Identifier: NCT02401893.
|Original language||English (US)|
|Journal||BMC infectious diseases|
|State||Published - Apr 23 2015|
Bibliographical noteFunding Information:
This research was supported by: K23 AI074863-01A1 (PI, Talbot HK), CDC 1 U18 IP000184-01 (PI, Griffin MR), CDC 5 U18 IP000183-02 (PI, Belongia EA), CTSA award No. UL1TR000445 from the National Center for Advancing Translational Sciences and the Atlantic Philanthropies (USA) Inc, the Infectious Diseases Society of America, the John A. Hartford Foundation, Inc., and the Association of Specialty Professors. The contents are solely the responsibility of the authors and do not necessarily represent official views of the Centers for Disease Control and Prevention and the National Center for Advancing Translational Sciences or the National Institutes of Health.
H. Keipp Talbot has received research funding from Sanofi Pasteur, MedImmune/Aztrazeneca and Giliead and is an advisor for Teva pharmaceuticals. Laura A. Coleman PhD, RD, currently works for Abbott Nutrition. At the time the study was conducted, she was at the Marshfield Clinic Research Foundation. Maria E. Sundaram, Edward A Belongia, and Marie Griffin have received research funding from MedImmune. Yuwei Zhu, Sarah Spencer, Mark Thompson, Po-Yung Cheng, and David Shay have no conflicts of interest.
© Talbot et al.; licensee Biomed Central.
- Older adults