A recent study in pigs has shown that inhaled vaccines could potentially reduce viral transmission and improve efficiency, marking a significant step toward advancing human vaccine development.
Since the SARS-CoV-2 pandemic in 2020, interest in administering vaccines mucosally, rather than through intramuscular injections, has grown. This method targets viruses at their point of entry and has the potential to enhance immune responses.
Scientists from the Pandemic Sciences Institute and The Pirbright Institute collaborated to explore immune system responses to mucosally administered flu vaccines using pigs as a model. The pig respiratory tract, which is anatomically and functionally similar to that of humans, allows researchers to study immune responses that are difficult to measure directly in human lungs.
Through this study, samples collected from both the lungs and blood of vaccinated pigs, combined with mathematical modeling, demonstrated that immune responses in the lungs could be reliably predicted from blood tests. This breakthrough simplifies the assessment of vaccine effectiveness in humans.
Professor Dame Sarah Gilbert, Saïd Professor of Vaccinology and PSI investigator, noted:
“The research found that immune responses in the blood could reliably reflect those in the lungs, offering a practical way to assess the effectiveness of vaccines targeting the respiratory system. These findings provide critical insights into how immune responses can be measured using accessible blood samples and form a foundation for future clinical trials of mucosally administered vaccines.”
Dr. Simon Gubbins, Head of Transmission Biology at The Pirbright Institute, added:
“To bring future vaccines to market, it is critical to define the correlates of protection—markers that reliably predict vaccine effectiveness in humans. Our study explored potential assays, sampling times, and sample types (such as blood and lung samples) that could establish these correlates of protection.”
Published in Frontiers in Immunology, the findings have significant implications for the future development of mucosally administered vaccines. By mimicking human immune responses to respiratory infections like influenza, the pig model provides an ideal platform for evaluating vaccine efficacy.
This research not only identifies effective biomarkers for mucosal vaccine efficacy but also highlights the best methods for monitoring and measuring immune protection. These advancements lay the groundwork for next-generation vaccines, offering improved protection against respiratory viruses and benefitting public health worldwide.
For more details, read the full paper in Frontiers in Immunology.
