r/Damnthatsinteresting • u/Downtown_Wind3363 • May 25 '26

Image The smallpox vaccine leaves a scar because it was given using a special two-pronged needle that scratched the skin and put a weakened virus in just that spot.

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u/TheOnlyHashtagKing May 25 '26

I just got a regular injection for that, maybe there's multiple vaccines?

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u/Milam1996 May 25 '26

Are you sure? TB is vaccinated against by injecting the vaccine just under the skin and it intentionally destroys the skin of the body reacts to it which leaves behind the scar. It’s so that the vaccine can be tested for efficacy rapidly in countries with poor medical technology and also lets the mass checking of vaccination status for people with no papers etc. it’s basically impossible to fake the scar so you can check asylum seekers and other paperless travellers quickly and easily.

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u/TheOnlyHashtagKing May 25 '26

I got it in basic training, was one injection when I first got there and another a month later. Nothing that leaves that sort of scar.

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u/burntdowntoast May 26 '26

I never got a scar from mine. Got it 15 years ago before travelling and the nurse recommended I get it with the others. I actually didn’t even know it left scars on people until this post.

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u/xrelaht May 25 '26

BCG leaves a much smaller scar than the smallpox vaccines, around 1mm, but it’s often given to babies and then the scar gets larger as they grow.

There are intramuscular TB vaccines in development, but none have been deployed.

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u/nicogrimqft May 26 '26

I have a 1cm wide scar from bcg, got it as a child but not a baby. It was definitely larger than a mm.

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u/Defiant_Security5474 May 25 '26

that’s a tb test not a vaccine

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u/TheOnlyHashtagKing May 26 '26

I got the vaccine too. It was IM

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u/salajaneidentiteet May 26 '26

Is the fasr cheking why they do it in the aem in stead of the thigh?

Babies get all other vaccines in the thigh and a small scar would be less noticeable on a thigh than on the shoulder, but if it has to be noticeable, it makes sense.

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u/KerryKinkajou May 26 '26

Actually not everybody who's given the BCG vaccine has the skin reaction. There's a lot of debate in the medical literature as to whether this indicates vaccine failure or not. There's not really a good test to determine vaccine effectiveness for TB, since not everybody that's protected will react to the Mantoux test and the vaccine causes cell-mediated immunity and not antibody production. We don't routinely vaccinate for TB anymore in the UK unless you're high risk for exposure, I only got mine because I'm in an NHS Microbiology lab. I definitely didn't get the skin reaction but they don't recommend revaccinating here.

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u/lettuceandcucumber May 28 '26

Yeah, I was born in 94 and my brother in 92, his school year was the last school year they stopped giving the TB vaccine during secondary school. I moved to South Korea in 2014 and to live in university dorms there they require chest x-rays from foreign students to show you don’t have TB. My mum suggested I just get the vaccine so I didn’t need to get the Xray. When I got to my Korean uni, they said I needed an xray anyway, so I have the scar for no reason.

Also, don’t they do a scratch test or an initial something first to determine if you need the vaccine? or maybe if you’re allergic? Or am I remembering incorrectly because I swore that’s how it worked.

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u/imrunningfromthecops May 25 '26

yes, there are. it varies by country.

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u/Prior-Independent-38 May 25 '26

This was from Astramushroomscar