The shingles vaccine can make your arm sore and give you muscle aches or fatigue for a day or two, and lots of people feel this — but it’s not serious and almost no one quits the study because of it.

The shingles vaccine called HZ/su doesn’t make you more likely to have serious health problems, autoimmune issues, or die compared to getting a fake shot — even after tracking people for over three years.

If you're 50 or older and your immune system is healthy, getting two shots of this special shingles vaccine, two months apart, cuts your chance of getting shingles by almost all the way down—like going from a 10% risk to less than 0.3%.

There’s a new shingles shot called HZ/su that works almost just as well for everyone over 50—whether they’re 50 or 80—while the old one, Zostavax, gets much less effective the older you are.