allegedly, people in that shingle sub said they got it under 50, for at least one guy it triggered some inflammation that damaged his “oats” temporarily, and another triggered shingles anyways. theres too much misinformation about taking it under 50. im guessing the stronger immune response would cause more inflammation than it useful, and since theres isnt really that much studies for under 50, you still can get shingles anyways. for 50+ the older you are, the more severe it is, so the shingles help reduce that effect, just dont know for people under 50, as the mentioned side effects. unless you are immunocompromised already, your provider/insurance wont reccomend at all. i think thats probably the only instance of getting under 50.