And it can't prevent certain kinds of cancer the way a healthy immune system can.

This is not a problem for most people because a healthy immune system can easily control it.

For most people with healthy immune systems, this is not a problem.

They usually do not occur in people who have healthy immune systems.

Are certain vitamins and minerals especially important for a healthy immune system?

These infections are unusual in people with a healthy immune system.

But the test requires a healthy immune system to be accurate.

Most people with healthy immune systems will recover without special treatment.

These were conditions not usually found in people with healthy immune systems.

Both of these cancer types are rare, especially in men with a healthy immune system.