Not everyone responds in the same way to influenza vaccines. In fact, the variability in effectiveness of the vaccine among older adults ranges from 17-53%, leaving a significant proportion of the population unprotected even when vaccinated.
Predicting vaccine responsiveness is challenging. As we get older, our immune systems age too - but not all at the same rate. The variation in rates at which people's immune systems age could be the reason for the differences in vaccine effectiveness. The VITAL project classified people into different ‘immunotypes’ based on their immune profile at the cellular level, to see whether this approach could increase the predictability of whether the vaccine would work in an individual or not.
VITAL researchers analysed the immune profiles of more than 300 people aged 25-98, both before and after they received a flu vaccine. They identified two pre-vaccination immunotypes, one of which was associated with a weak response and one with a strong response. These results highlighted that age is not a good predictor of flu vaccine responsiveness whereas baseline immune profiles are.
Lead author, Alper Çevirgel of the Center for Infectious Disease Control at the National Institute for Public Health and the Environment in the Netherlands, said: "Our study, utilising the innovative concept of immunotypes, has unveiled critical insights into how individual immune profiles influence the response to influenza vaccination. By identifying specific immunotypes associated with weak and robust antibody responses, we have uncovered crucial insights into the immune system's baseline state and its response to vaccination.”
This work could help to identify those individuals who would most benefit from a flu vaccine, with a view to developing new vaccination strategies for those individuals who are not protected via current vaccines.
“This research, enabled by the Innovative Medicines Initiative framework, paves the way for personalised vaccination strategies, particularly in aging populations. It highlights the importance of considering individual immune system profiles in vaccine response, which could revolutionise our approach to immunisation and overall healthcare,” said Çevirgel.
VITAL was supported by the Innovative Medicines Initiative, a partnership between the European Union and the European pharmaceutical industry.