We study the molecular details of why viruses infect us and cause severe disease, as understanding our natural defences will help assess the risk posed by emerging viruses and enable the development of new interventions.
Each year, seasonal influenza causes around one billion infections worldwide, including 3–5 million cases of severe illness and up to 650,000 respiratory deaths.
Influenza A is the type of flu virus causing these seasonal outbreaks, and it naturally circulates in wild birds. Avian influenza, or bird flu, has historically caused particularly severe disease in humans, with strains such as H5N1 associated with fatality rates of over 40%.
We found that a small increase in body temperature, similar to a common fever, can completely transform the course of influenza A infection.
However, some strains are more sensitive to fever than others, and our findings help explain why some flu viruses cause more serious illness, and why the strains responsible for the deadly pandemics of 1918, 1957 and 1968 were more severe than their seasonal counterparts.
Our research is shaping how we think about influenza risk and patient care. By identifying genetic features that allow some viruses to resist fever, we can help pinpoint emerging flu strains that may be more virulent and pose a higher pandemic risk.
At the same time, we are examining how the routine use of fever-reducing medicines may influence disease outcomes, particularly where suppressing fever could limit the body’s natural ability to control infection.
Our ultimate goal is to use these insights to better predict which viruses might spill over into human populations and to improve patient outcomes.
CITIID is a wonderful place to be embedded as a scientist, and one of its great strengths is the sheer diversity of work that's going on in the sphere of infection and immunity.
Here we have people studying populations, individuals, organs and systems, down to the level of cells and even individual molecules.
I've been able to collaborate with people who have expertise in a vast range of animal models, alongside experts in computational approaches, such as analysing cohorts of infected patients, to look at how genetic variation in populations might affect infectious diseases.
Bringing together expertise across all of these scales allows us to connect individual discoveries to their wider impact on human health.
References
- WHO. Influenza (seasonal) fact sheet. 2022. https://www.who.int/news-room/fact-sheets/detail/influenza-(seasonal)
- Turnbull ML, Wang Y, Clare S, et al. Avian-origin influenza A viruses tolerate elevated pyrexic temperatures in mammals. Science. 2025;390(6776):eadq4691. doi:10.1126/science.adq4691
Credits:
Image credit: Adobe Stock, University of Cambridge