Does prior vaccination affect the immune response to seasonal influenza vaccination among older adults? Findings from a prospective cohort study in a Northeastern Province of Thailand
Issued Date
2023-02-01
Resource Type
eISSN
19326203
Scopus ID
2-s2.0-85147458150
Pubmed ID
36735691
Journal Title
PLoS ONE
Volume
18
Issue
2 February
Rights Holder(s)
SCOPUS
Bibliographic Citation
PLoS ONE Vol.18 No.2 February (2023)
Suggested Citation
Praphasiri P., Prasert K., Shrestha M., Ditsungnoen D., Chittaganpich M., Chawalchitiporn S., Dawood F.S., Sirilak S., Mott J.A. Does prior vaccination affect the immune response to seasonal influenza vaccination among older adults? Findings from a prospective cohort study in a Northeastern Province of Thailand. PLoS ONE Vol.18 No.2 February (2023). doi:10.1371/journal.pone.0279962 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/82153
Title
Does prior vaccination affect the immune response to seasonal influenza vaccination among older adults? Findings from a prospective cohort study in a Northeastern Province of Thailand
Other Contributor(s)
Abstract
Background We measured the immunogenicity of seasonal trivalent inactivated influenza vaccines (IIV3) among older Thai adults and the effect of one-year prior vaccination status on immune responses. Method Adults aged ≥65 years (n = 370) were vaccinated with Southern Hemisphere IIV3 in 2015. Hemagglutination inhibition assays were performed using goose red blood cells on sera collected from the participants at baseline and after 1, 6, and 12 months of vaccination. Prior year vaccination (in 2014) was verified with the national health security office database. We analyzed the associations between prior vaccination and geometric mean titers (GMT) at each time point using generalized linear regression on logged transformed titers, and seroprotection and seroconversion using Log-binomial regression. Results At baseline, previously vaccinated participants (n = 203) had a significantly higher GMT and seroprotection against all three influenza strains than those previously unvaccinated (n = 167) (all p-values <0.001). Seroprotection rates were similar after one month in both groups for A(H1N1)pdm09 (adjusted risk ratio [aRR] 1.10, 95% CI 0.97–1.25), and A(H3N2) (aRR 1.08, 95% CI 0.87–1.33), but higher in previously vaccinated persons for B (aRR 1.20, 95% CI 1.08–1.32). At 12 months, 50% or more had seroprotection in previously vaccinated group with no difference between previously vaccinated or unvaccinated persons. Seroconversion was lower in the previously vaccinated group for A(H1N1)pdm09 (aRR 0.62, 95% CI 0.43–0.89), but did not differ between the two groups for A(H3N2) (aRR 0.94, 95% CI 0.69–1.28) and B (aRR 0.85, 95% CI 0.60–1.20). Conclusion Influenza vaccination elicited good humoral response in older Thai adults. While seroconversion seemed attenuated in persons previously vaccinated for influenza A(H1N1)pdm09 (the only vaccine strain not to change), this was not apparent for influenza A(H3N2) and B, and prior vaccination was not associated with any inhibition in seroprotection.