Could the shingles vaccine prevent or delay new-onset dementia? Ontario-based study suggests so – CTV
January 27, 2026
A new Ontario-based study is suggesting the shingles vaccine may help prevent and/or delay the onset of dementia more effectively than any existing treatment.
The study was published in Lancet Neurology and led by researchers at McMaster University and Stanford University. It analyzed health data from more than 250,000 seniors in Ontario and found the herpes zoster vaccination, also known as the shingles vaccine, helped significantly prevent dementia.
“There’s no pharmacological tool that has been shown to have such a large preventative effect,” Pascal Geldsetzer, lead researcher and Stanford University professor, told CTV News Toronto.
The study is rooted in Ontario’s shingles vaccine program introduced in September 2016. When Ontario first introduced the program, people who had their 71st birthday after Jan. 1, 2017, were eligible for the free vaccine whereas people who had their 71st birthday before this date were not – naturally creating two groups of people born immediately on either side of the cutoff date.
