New research published in Nature has shown that the recombinant shingles vaccine, as with the live version, might have a protective effect against dementia.
While evidence is emerging that the live herpes zoster (shingles) vaccine might protect against dementia, it has now been replaced by recombinant vaccines in many countries. But a lack of data meant that whether the recombinant vaccines conferred the same benefit was unknown. Fortunately, since there was a rapid switch from live to recombinant vaccines, there was an opportunity for a natural experiment to compare the risk of dementia between vaccine types.
The study demonstrated that the recombinant vaccine is associated with a significantly lower risk of dementia in the 6 years post-vaccination. Specifically, receiving the recombinant vaccine is associated with a 17% increase in diagnosis-free time, translating into 164 additional days lived without a diagnosis of dementia in those subsequently affected.
The recombinant shingles vaccine was also associated with lower risks of dementia than were two other vaccines commonly used in older people: influenza and tetanus–diphtheria–pertussis vaccines. The effect was robust across multiple secondary analyses, and was present in both men and women but was greater in women. These findings should stimulate studies investigating the mechanisms underpinning the protection and could facilitate the design of a large-scale randomised control trial to confirm the possible additional benefit of the recombinant shingles vaccine.
