Q. Can I get shingles from another person?

A. No, you can’t, and here’s why:

Shingles is caused by a virus called varicella-zoster virus – “VZ virus” or just “VZV.” Almost all adults have been infected with this virus. Many became infected in childhood. Once you are infected with this virus, it remains alive in your body for the rest of your life.

When children are first infected with VZV, it often causes chickenpox. When an adult is infected with VZV for the first time, a more severe illness – most often pneumonia – can occur.

Sometimes the infection comes on without causing any symptoms. The virus just enters the body through the throat, and then travels to the nerves. For most or all of our lives the virus just lives “asleep” inside the nerves, causing no symptoms. That’s because our immune system is keeping it in check.

But sometimes the immune system can have temporary lapses. This happens more often as we grow older. But it can happen at any time in our lives. As a result, the virus that’s asleep inside the nerves can start to multiply. When that happens, the skin supplied by the nerve starts to tingle and get unpleasant sensations. Often the skin gets red and forms little blisters. That’s the illness called shingles.

So you get shingles from a virus that entered your body years before, usually when you were a kid. You can’t catch it from even close contact with another person who’s having an attack of shingles. That’s in part because the virus that causes shingles, VZV, is likely already in your body.

Dr. Howard LeWine is a practicing internist in Boston, Mass.