A new study found that there could be some viral illnesses that might increase a person’s chance of developing Alzheimer’s disease. 

The strongest association was between viral encephalitis and Alzheimer’s disease. People who had that illness were 20 times more likely to get an Alzheimer’s diagnosis compared to those who never contracted it, according to the National Institute on Aging. 

The researchers found nearly two dozen connections between a neurodegenerative disorder and a previous viral infection that led to a hospital visit.

The study, which appeared in the journal Neuron, also suggests that vaccinations could help reduce the chances of developing a neurodegenerative disorder like dementia or Parkinson’s disease.