A recent study suggests that vaccines designed to protect against respiratory infections may also provide unexpected benefits for brain health. Researchers found that adults who received a vaccine for respiratory syncytial virus (RSV) appeared to have a lower risk of developing dementia. This was compared with those who did not receive the vaccine.
Furthermore, it analyzed medical records from more than 430,000 adults in the United States. Scientists compared individuals who received the RSV vaccine Arexvy with those who received only the seasonal flu vaccine. According to the findings, adults vaccinated against RSV experienced approximately a 29% lower rate of dementia diagnoses during the following 18 months.
Protective Effect of AS01
Researchers believe the protective effect may be linked to a special ingredient called AS01, an immune-boosting adjuvant included in the RSV vaccine. The same adjuvant is also used in the shingles vaccine Shingrix, which previous studies have similarly associated with reduced dementia risk. Moreover, since both vaccines produce comparable effects, scientists think the adjuvant itself may play an important role in protecting brain health.
Although the exact mechanism remains unclear, laboratory studies suggest that AS01 strongly activates the immune system and may help reduce inflammation and other harmful biological processes linked to neurodegenerative diseases.
The study does not prove that RSV vaccination completely prevents dementia. Instead, experts say it may help delay the onset or lower the likelihood of developing the condition.
Scientists caution that additional long-term research is still necessary to confirm the results and better understand how vaccines may influence cognitive health.
“Our findings show that vaccines against two separate viruses, shingles and RSV, both lead to reductions in dementia. This gives another reason to have the vaccines, in addition to their effectiveness at preventing these serious illnesses.”
said Lead author Associate Professor Maxime Taquet, NIHR Academic Clinical Lecturer, Department of Psychiatry, University of Oxford
