'The first double-blinded randomised clinical trial to test the effectiveness of antivirals against dementia is now under way. A group of researchers mostly based at Columbia University are testing whether valacyclovir, an antiviral used against HSV1, can slow down cognitive decline in people with early stage Alzheimer’s. Between 2018 and 2024, the researchers recruited 120 patients and treated half with the antiviral. They expect to publish their findings later this year. John Hardy, whose research forms the basis of the dominant amyloid theory of Alzheimer’s, and who has been a critic of the virus theory, says that a positive result in this trial would begin to convince him otherwise. If Dr Geldsetzer and his team can secure the funding, a similar trial of the shingles vaccine may soon follow.'