A microscopic parasite that can live for decades in the human brain infects an estimated one-third of the world's population ...

During the recent Covid-19 pandemic, the rate of serious illness and death was jarringly high in older populations. Why? Weakening immune systems — as we age, we become more vulnerable to infections, ...

Antibodies, which recognize viruses and proteins that the body has encountered before, have long gotten most of the credit for giving the human immune system a memory. Now, researchers at the ...