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COVID-19

COVID-19 Research Reveals Importance of Humoral and Cell-Mediated Immunity in Influenza Vaccination

Strategic Insights

— 1 min read

Researchers from Hyogo Medical University in Japan conducted a study to evaluate the humoral and cell-mediated immune responses induced by an inactivated influenza vaccine (IIV4) during the 2019/2020 influenza season. The study, which was supported by the Hyogo Medical University Grant For Research Promotion and the Japan Society For The Promotion of Science, found that the geometric mean titer ratio for A/H3N2 exceeded 2.5, meeting the criteria outlined by the European Medicines Agency guidelines. However, other strains did not achieve similar thresholds. The study also highlighted the importance of both humoral and cell-mediated immunity in evaluating vaccine immunogenicity.

Key Takeaways:

  • The study evaluated the humoral and cell-mediated immune responses induced by an inactivated influenza vaccine (IIV4) in 25 healthy adults during the 2019/2020 influenza season in Japan.
  • The geometric mean titer ratio for A/H3N2 exceeded 2.5, meeting the criteria outlined by the European Medicines Agency guidelines.
  • Other strains did not achieve similar thresholds.
  • IFN-g responses indicated significant activation for all strains, with 32-36% of participants exhibiting 1.5-fold increases.
  • The study highlights the importance of both humoral and cell-mediated immunity in evaluating vaccine immunogenicity.
  • Naruhito Otani, a researcher at Hyogo Medical University, led the study, which was supported by the Hyogo Medical University Grant For Research Promotion and the Japan Society For The Promotion of Science.
  • Additional authors on the study include Toshiomi Okuno, Kumiko Yamada, Toshie Tsuchida, Kaori Ishikawa, Kaoru Ichiki, Takashi Ueda, Yoshio Takesue, Satoshi Higasa, and Kazuhiko Nakajima.

Statistics:

  • 25 healthy adults participated in the study.
  • The geometric mean titer ratio for A/H3N2 exceeded 2.5.
  • 32-36% of participants exhibited 1.5-fold increases in IFN-g responses.
  • The study used an inactivated influenza vaccine (IIV4).
  • The study was conducted during the 2019/2020 influenza season in Japan.

Sources:

  • "Evaluation of Humoral and Cell-Mediated Immunity Induced by Quadrivalent Influenza Vaccine in Pre-COVID-19 Japan" (Viruses, 2025, 17(5):626).
  • MDPI AG, the publisher of Viruses (http://www.mdpi.com/journal/viruses).
  • NewsRx LLC, the publisher of Medical Letter on the CDC & FDA (Copyright 2025, NewsRx LLC).
  • NewsRx. New COVID-19 Research Reported from Hyogo Medical University (Evaluation of Humoral and Cell-Mediated Immunity Induced by Quadrivalent Influenza Vaccine in Pre-COVID-19 Japan). Medical Letter on the CDC & FDA. June 15, 2025; p 158.

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