Immunogenicity and safety of quadrivalent influenza vaccine among young and older adults in Tianjin, China: implication of immunosenescence as a risk factor

Tongling Xiao; Miaomiao Wei; Xiaokun Guo; Yu Zhang; Zhongyan Wang; Xiaoshuang Xia; Xuemei Qi; Lin Wang; Xin Li; Sean X Leng

doi:10.1186/s12979-023-00364-6

Immunogenicity and safety of quadrivalent influenza vaccine among young and older adults in Tianjin, China: implication of immunosenescence as a risk factor

Immun Ageing. 2023 Jul 27;20(1):37. doi: 10.1186/s12979-023-00364-6.

Authors

Tongling Xiao^#¹, Miaomiao Wei^#¹, Xiaokun Guo², Yu Zhang², Zhongyan Wang², Xiaoshuang Xia¹, Xuemei Qi¹, Lin Wang², Xin Li³, Sean X Leng^{4

5}

Affiliations

¹ Department of Neurology, The Second Hospital of Tianjin Medical University, 23 Pingjiang Road, Tianjin, 300211, China.
² Department of Geriatrics, The Second Hospital of Tianjin Medical University, Tianjin, China.
³ Department of Neurology, The Second Hospital of Tianjin Medical University, 23 Pingjiang Road, Tianjin, 300211, China. lixinsci@126.com.
⁴ Division of Geriatric Medicine and Gerontology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. sleng1@jhmi.edu.
⁵ School of Medicine and Bloomberg School of Public Health, Division of Geriatric, Johns Hopkins Center On Aging and Immune Remodeling, Johns Hopkins University, JHAAC Room 1A.38A, 5501 Hopkins Bayview Circle, Baltimore, MD, 21224, USA. sleng1@jhmi.edu.

^# Contributed equally.

Abstract

Background: Older adults are more vulnerable to seasonal influenza than younger adults. The immune responses of older persons to the influenza vaccine are usually poorer than those of young individuals, which is hypothesized due to immunosenescence. We conducted a study to evaluate the immunogenicity and safety of a quadrivalent inactivated influenza vaccine (IIV4) in a total of 167 young (< 65 years, n = 79) and older (≥ 65 years, n = 88) adults from October 2021 to March 2022 in Tianjin, China. A single dose was administered to all participants. Blood samples were collected and strain-specific hemagglutination inhibition (HAI) antibody titers were measured before and 21 to 28 days after vaccination. Safety information was also collected for 28 days and 6 months after vaccination. Differences in immunogenicity and safety were compared between young and old age groups, and multivariate logistic regression was used to estimate the effect of age and other factors on HAI antibody responses.

Results: Overall, geometric mean titers (GMTs) against all four vaccine strains in older adults were lower than those in the young, whereas the seroconversion rates (SCRs) were similar. Multivariate logistic regression analysis showed that age, influenza vaccination history, and pre-vaccination HAI titers were independent factors affecting SCRs and seroprotection rates (SCRs). Older age had significant negative impact on SCRs against H1N1 (OR, 0.971; 95% CI: 0.944-0.999; P = 0.042) and B/Victoria (OR, 0.964; 95% CI: 0.937-0.992; P = 0.011). In addition, there was a significant negative correlation between chronological age (years) and post-vaccination HAI titers against H1N1 (rho = -0.2298, P < 0.0001), B/Victoria (rho = -0.2235, P = 0.0037), and B/Yamagata (rho = -0.3689, P < 0.0001). All adverse events were mild (grade 1 or grade 2) that occurred within 28 days after vaccination, and no serious adverse event was observed.

Conclusions: IIV4 is immunogenic and well-tolerated in young and older adults living in Tianjin, China. Our findings also indicate that age is an independent factor associated with poorer humoral immune responses to IIV4.

Keywords: Aging; Immunogenicity; Immunosenescence; Older adults; Quadrivalent inactivated influenza vaccine; Safety.

Abstract

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