Researchers conducted a study on a Welsh vaccination program that focused on the live-attenuated shingles vaccine and its potential impact on dementia risk. The study found that women who received the shingles vaccine had a lower likelihood of being diagnosed with dementia compared to men. This effect was more prominent in women, with a 20% relative reduction in dementia risk. The researchers suggest that the vaccine may help prevent dementia by curbing shingles infections, which have been linked to dementia development. They also propose that the vaccine may affect the immune system in ways that prevent or delay dementia onset.
To investigate the relationship between shingles vaccination and dementia risk, the researchers used a natural experiment in Wales. By comparing individuals born just before and after the eligibility date for the vaccination program, the researchers were able to create a randomized controlled trial-like setting. This approach allowed them to mitigate bias that can arise in studies comparing vaccinated and unvaccinated individuals. The study tracked dementia diagnoses for over 280,000 individuals born between 1925 and 1942 and observed a significant decline in dementia risk with later birth dates following eligibility cutoff for vaccination.
While the study focused on the live-attenuated shingles vaccine used in the Welsh program, other studies have shown that the recombinant shingles vaccine also lowers dementia risk. The authors acknowledge that future research should explore the effects of the recombinant vaccine, given that it was replaced the live-attenuated version in the United States in 2020. The findings from these studies provide valuable insights into the potential benefits of shingles vaccination beyond preventing the illness, including reducing the risk of developing dementia.
Overall, the study highlights the importance of vaccination programs in potentially reducing the risk of dementia. By preventing shingles infections and their associated complications, vaccines like the live-attenuated and recombinant shingles vaccines may play a role in protecting against cognitive decline and dementia. Further research on the mechanisms by which these vaccines influence dementia risk, particularly among different population groups, will be crucial in understanding the full potential of vaccination as a preventive strategy for dementia.
