Recent research indicates that vaccines for shingles and respiratory syncytial virus (RSV) may reduce the risk of dementia. The study highlights the shingles vaccine, Shingrix, which is more effective than its predecessor Zostavax due to an ingredient called an adjuvant that enhances the vaccine's effect.
The study, backed by the National Institute for Health and Care Research Oxford Health Biomedical Research Centre, analyzed health records from over 430,000 individuals in the USA using the TriNetX network. Researchers found that Arexvy, a vaccine against RSV offered to adults over 60, was associated with a significantly lower risk of developing dementia. Notably, Arexvy contains the same adjuvant as Shingrix. In comparison to flu vaccines lacking this adjuvant, both Shingrix and Arexvy showed similar effectiveness in reducing dementia risk. Specifically, there was a 29% reduction in dementia diagnoses within 18 months following Arexvy vaccination.
The mechanism by which the adjuvant AS01 might lower dementia risk remains unclear. However, laboratory studies suggest AS01 stimulates immune cells that could protect the brain from processes underlying dementia. These potential benefits are additional to preventing infections like shingles and RSV.
It remains uncertain whether these vaccines prevent or delay dementia onset. Regardless, their impact is significant since no other treatments currently delay or prevent dementia.
Associate Professor Maxime Taquet from the University of Oxford stated: “Our findings show that vaccines against two separate viruses, shingles and RSV, both lead to reductions in dementia.” Senior author Professor Paul Harrison emphasized: “The findings are striking. We need studies to confirm whether the adjuvant present in some vaccines contributes to the reduced dementia risk.”
The paper titled ‘Lower risk of dementia with AS01-adjuvanted vaccination against shingles and respiratory syncytial virus infections’ has been published in npj Vaccines.