Understanding immunity towards seasonal Influenza vaccines

Our congratulations to Professor Katherine Kedzierska and colleagues on the publication of their recent research in Science Translational Medicine  (Department of Microbiology & Immunology)

Current annual influenza vaccinations are the most effective strategy to blunt the impact of seasonal influenza infections and protect us from severe influenza disease. However, the efficacy of influenza vaccines varies from year to year and between individuals. The present study provides exciting insights into how the immune system responds to influenza vaccinations and how long-term immunological memory resides in human tissues.

In the current Science Translational Medicine paper the researchers questioned what components of the immune system respond to the current influenza vaccines and how protective immunity is generated. The findings identified three main types of white blood cells, namely T follicular helper cells, antibody-secreting cells and memory B cells, associated with successful influenza vaccination in people who responded to the vaccine. The researchers also found that the current vaccination strategies do not, however, elicit other lymphocyte subsets in the human circulation such as killer T cells. Importantly, dissection of memory B cells across different types of human tissues showed that the long-term immunological memory to influenza viruses resides outside the circulation.

schematic showing long-term immunological memory to influenza viruses resides outside the circulation

The results have implications for designing improved influenza vaccines by better targeting specific cell types required for optimal influenza vaccine efficacy and suggest that targeting a wider range of white blood cells should be considered for a one-shot universal influenza vaccine.

The findings can also assist clinicians in making early predictions of how well a patient’s immune system responds to influenza vaccination, which is particularly important for high risk patients who are at risk of dying.

Published in Science Translational Medicine, the research is a collaboration between the University of Melbourne, WHO Collaborating Centre for Reference and Research on Influenza, Seqirus, Mercy Hospital for Women, St Vincent’s Institute, Alfred Hospital, University of Sydney and Garvan Institute.

The study was led by Professor Katherine Kedzierska and Dr Oanh Nguyen from the Department of Microbiology and Immunology at the Doherty Institute. Marios Koutsakos, a PhD student in Kedzierska laboratory, worked with Melbourne experts on the research.