Infections like pneumonia can speed up dementia. Vaccinations can prevent infections but don’t always work in older adults. We need new drugs to keep aging brains healthy after infections. We found that after mice recover from pneumonia they experience something like dementia. When we gave them a drug called 5’-AZA that reversed some of the changes to their aging immune systems, they did not have as many learning and behaviour problems after they recovered.

Our vision is that when doctors are treating patients for pneumonia, they would give them this drug to keep their brains healthy. Before we can do this in people, we must try it in mice. We will do this by 1) testing whether giving the drug during an infection prevents learning and behaviour changes in mice and 2) determining whether the drug works by helping the body clear harmful inflammation in the blood and brain.

We think we are the first researchers to use mice to investigate brain changes after pneumonia. We can investigate what happens to immune cells in the brain after an infection, which we can’t do in people. We are excited to try to use the drug 5’-AZA because it is already used in people for other conditions. This means that if our experiments in mice look promising, we can work towards testing it in humans.

No one knows why infections speed up dementia. We suspect that changes in the aging immune system are part of the problem. We chose a drug that would ‘undo’ some changes to the aging immune system and would be safe t o give sick people. If our tests in mice work, we can start developing this drug for people. Even if our drug doesn’t work, we will learn what happens in the brain after infection.

Serious respiratory infections like pneumonia can speed up dementia. Preventing infections would give older adults more years of health and independence. Vaccines help but don’t always work. We want to understand what happens in the brain after an infection to figure out how to stop dementia and to test a drug in mice to see if we can prevent dementia after infections. It is essential to try this in mice before using it in people.