In October 2023 the University of Oxford’s Oxford Vaccine Group announced funding from the Medical Research Council within UK Research and Innovation (UKRI) to support a “pioneering” study into human immunity. The study is called LEGACY03 and will investigate how lymph nodes work and contribute to vaccine responses in patients of different ages. This research will potentially inform vaccine design for different age groups.  


The study is open to participation from volunteers between the ages of 18 and 45 and over the age of 65. It will take place at the Churchill Hospital’s Centre for Clinical Vaccinology and Tropical Medicine. Participants will be enrolled for 3 months, with the results supporting better vaccine design for “different age groups throughout life”. Participants will be given two licensed vaccines: an mRNA COVID-19 booster vaccine and a seasonal flu jab.  

“As we age, our immune system changes and with it our response to vaccines. Our risk of complications from infections like flu and COVID-19 also increases and it is therefore important to understand these changes so that vaccinations can be better tailored for maximum efficacy to protect the most vulnerable.”  

Dr Katrina Pollock, MRC Clinician Scientist in Vaccinology at the Oxford Vaccine Group, Department of Paediatrics, was “keen to improve understanding of the immune system” and respond to the “challenges in adult vaccinology”, which she suggests are “two-fold”.  

“The first major challenge is the diversity of responses to vaccines in different people, particularly the most vulnerable like older adults or those living with conditions that affect the immune function. The second major challenge is making vaccines for targets that rapidly evolve, like COVID-19 and HIV.” 

Dr Pollock states that the study will “take an innovative look” at individual immune responses, investigating human immunity “at the cellular level”.  

“This will help us to tailor future vaccine design to get a better outcome for patients across the board. It has the potential to impact patients for the better and that is what drives my research.”  
Lymph nodes 

Lymph nodes are “small bean shaped organs” that can be found all over the body. When a vaccine is administered, white blood cells transport some of the vaccine back to the lymph nodes for a response to happen. In this study, the lymph nodes will be visualised with an ultrasound scanner and cells extracted to understand how they are responding. The cells will be sampled using the “safe and well-tolerated” technique, fine needle aspiration (FNA).  

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