Scientific Reports (Jun 2021)

Effective inactivated influenza vaccine for the elderly using a single-stranded RNA-based adjuvant

  • Yoo-Jin Bang,
  • So-Hee Hong,
  • Hyo-Jung Park,
  • Hye Won Kwak,
  • Yu-Sun Lee,
  • Jae-Yong Kim,
  • Hyeong-Jun Park,
  • Seo-Hyeon Bae,
  • Hye-Jung Kim,
  • Yun-Hee Kim,
  • Hae Li Ko,
  • Sang-In Park,
  • Hun Kim,
  • Gyeongjoo Park,
  • Man-Seong Park,
  • Jun Chang,
  • Jae-Hwan Nam

DOI
https://doi.org/10.1038/s41598-021-91445-3
Journal volume & issue
Vol. 11, no. 1
pp. 1 – 12

Abstract

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Abstract There is an unmet need for new influenza vaccine strategies that compensate for impaired vaccine responses in elderly individuals. Here, we evaluated the effectiveness of a single-stranded RNA (ssRNA) as an adjuvant to enhance the efficacy of inactivated influenza vaccine (IIV) in mouse models. Immunization with the ssRNA along with IIV reduced viral titers as well as pathological and inflammatory scores in the lungs after influenza challenge in aged mice. ssRNA induced balanced Th1/Th2 responses with an increase in IgA titers. Moreover, the ssRNA adjuvant markedly increased the frequency of influenza HA-specific T cells and IFN-γ production along with the expression of genes related to innate and adaptive immune systems that could overcome immunosenescence in aged mice. Our findings indicate that ssRNA is an efficient vaccine adjuvant that boosts cellular and humoral immunity in aged mice, demonstrating its potential as a novel adjuvant for currently available influenza virus vaccines for elderly individuals.