For young men like Rich P., who wonders what's in store for him in the decades ahead, this would appear to be an enormous scientific misstep—particularly since Rich believes he's seen firsthand the link between herpes and Alzheimer's.
His girlfriend's father, the one who passed away from Alzheimer's? He battled cold sores all his life.
Itzhaki says there are two reasons why herpes became a Virus of Interest in the hunt for an Alzheimer's cause. First was the observation, almost three decades ago, that a rare infection called herpes encephalitis affects the same regions of the brain that Alzheimer's does. Like people with Alzheimer's, encephalitis patients can be plagued by memory problems. The other factor, she says, is the prevalence of the herpes virus itself.
"Most people get it as children," Itzhaki says. "It's in your saliva, and it can easily be passed along with a kiss from a family member." She says it's not really that puzzling that most people who carry the virus never show symptoms—as she puts it, not everyone who's infected with a microbe is necessarily affected by it. "It depends on the person harboring the virus," she says. "It's probably based on genetic factors."
How might a germ you could have contracted from, say, a grandparent potentially destroy your brain when you become a grandparent?