Chicken pox and shingles are from the same herpes virus. Having either chicken pox or a chicken pox vaccine do give you some immunity, but the sad truth is that we lose memory B-cells as we age. So people do get shingles even though they had some immunity earlier against the virus. Apparently the Shingrix vaccine is very good: Like >90% effective.

But there is a caveat. CDC says: If you test negative for immunity to varicella zoster virus, you should get chickenpox vaccine instead.

Interesting factoid: Studies show that more than 99% of Americans 40 years and older have had chickenpox, even if they don’t remember having the disease.


We're flying electric helicopters on Mars yet you can't turn on your clothes dryer in Texas. That's because scientists are in charge of Mars, and Republicans are in charge of Texas.