Dr Michelle Linterman investigates the biology behind strong and weak responses to the flu vaccine. We reported on the early results of her study here. Here’s an update now the project is drawing to a close.

Working with her team at the Babraham Institute near Cambridge over the past two years, Dr Linterman has made significant progress in unravelling the causes of a poor response to the flu vaccine in the immune system of many older people.

Michelle’s research has focused on memory B cells, which are the white blood cells that rapidly respond to infection by becoming antibody-secreting cells. They survive in the body for years, providing a repeated and accelerated immune response to a recognised virus or bacteria. Blood samples have been taken from volunteers both before and after flu vaccination. Samples taken from volunteers following vaccination show a 50% increase in the number of memory B cells in those aged 18 to 35, compared to volunteers aged over 65.

“No one has examined flu-specific memory B cells in such detail before. We are really excited about this important breakthrough in our understanding. The question now is why this happens? This isn’t yet clear, but I believe it’s likely to be linked to the ‘germinal centre’ response. Germinal centres are sites within tissues where memory B cells form and this may not be happening so effectively in older individuals. We can now begin to think about ways to boost memory B cell production in older people after vaccination to help them resist flu infections more successfully,” comments Michelle.

A second intriguing finding relates to the many subtypes of B cells. “We have found a subtype of atypical memory B cells, which has been considered rare and not present in the immune response to vaccination. It may be more common than previously thought; its role in the immune response is unknown, but its presence seems to relate to a successful germinal centre response. It may be possible to modify vaccines so they stimulate production of these atypical memory B cells and this could be a fruitful line of enquiry for future research.”

Dr Michelle Linterman’s draft paper on the conclusions of her research is now in the peer review stage. To read it online visit: https://www.biorxiv.org/content/10.1101/2021.03.04.433942v1