# Why does the polio vaccine leave a mark on the arm? **URL:** \ **Category:** Factual Questions\ **Created:** [August 30, 2011, 7:30am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599 "2011-08-30T07:30:44Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Cat\_Whisperer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cat_whisperer/32/4839_2.png) [@Cat\_Whisperer](https://boards.straightdope.com/u/Cat_Whisperer)\ **Post date:** [August 31, 2011, 5:29am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/21 "2011-08-31T05:29:01Z")
> [@naita](#): > > \ > > In Norway mandatory vaccination stopped in 1976. I was born in '75 and have the scar, my younger brother in '77 and doesn’t. The last vaccinations performed in Norway were in 1980.\ My two older sisters were born in '63 and '64 and they both got the vaccination. I was born in '66 and I didn’t. I’ve always kind of wished I had it, but if it doesn’t last anyway, I guess it doesn’t matter. ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [August 31, 2011, 7:07am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/22 "2011-08-31T07:07:50Z")
My mother had an inch wide smallpox vaccination mark the outside of her thigh, about four inches above her knee. They put it there so “it would never show.” I have been vaccinated for small pox seven times, and never got a scar. Twice I was vaccinated **because** I had no scar. (I changed school systems rather a lot.) I have always believed that I originally gained a very strong immunity to smallpox because my mother got vaccinated while pregnant with me. I have been told that that is unlikely, but I have never had so much as a sore arm from them. Tris ---
**Author:** ![Triskadecamus](https://avatars.discourse-cdn.com/v4/letter/t/b19c9b/32.png) [@Triskadecamus](https://boards.straightdope.com/u/Triskadecamus)\ **Post date:** [August 31, 2011, 7:10am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/23 "2011-08-31T07:10:25Z")
> [@Chefguy](#): > > Read _[The Demon in the Freezer](http://www.amazon.com/Demon-Freezer-Richard-Preston/dp/0345466632/ref=sr_1_8?s=books&ie=UTF8&qid=1314766668&sr=1-8)_, if you think smallpox is not still a threat. It was eradicated in the public domain, but strains were kept alive in weapons labs in both the Soviet Union and the USA. Weaponized smallpox was (and possibly still is) a very real threat. The smallpox vax you were given as a child has been ineffective for a very long time, since it only protects you for about five years. People who work in labs where contamination is a possibility get boosters every year. Actually, although the protection is much reduced over decades, there is some reason to believe that survival, as opposed to immunity is still somewhat improved even thirty or forty years after initial vaccination. Tris ---
**Author:** ![needscoffee](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/needscoffee/32/1076_2.png) [@needscoffee](https://boards.straightdope.com/u/needscoffee)\ **Post date:** [August 31, 2011, 7:26am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/24 "2011-08-31T07:26:14Z")
My daughter, born in 1995, was vaccinated against smallpox in the Philippines as an infant. ---
**Author:** ![Bartman](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@Bartman](https://boards.straightdope.com/u/Bartman)\ **Post date:** [August 31, 2011, 1:04pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/25 "2011-08-31T13:04:15Z")
> [@LavenderBlue](#): > > Do they still use the smallpox in the US military? I’ve heard that they do from a friend of a friend. I believe so, yes. [http://www.smallpox.mil/](http://www.smallpox.mil/) ---
**Author:** ![Freudian\_Slit](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@Freudian\_Slit](https://boards.straightdope.com/u/Freudian_Slit)\ **Post date:** [August 31, 2011, 1:45pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/26 "2011-08-31T13:45:41Z")
> [@VOW](#): > > TB is not a vaccine, it is a test to see if your body is sensitized to the TB bacterium. A small amount of the TB bacteria would be deposited under the skin. A reaction would indicate that at some time, the person had been exposed to TB. It does not indicate an active infection, and it will always show positive, for the rest of your life. Are you saying there’s no such thing as a TB vaccine? Because I know I’ve had it. I’ve also had the test where I tested positive because I’d already been vaccinated. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 31, 2011, 2:27pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/27 "2011-08-31T14:27:06Z")
> [@Triskadecamus](#): > > Actually, although the protection is much reduced over decades, there is some reason to believe that survival, as opposed to immunity is still somewhat improved even thirty or forty years after initial vaccination. > > Tris Perhaps, but those who work with such things create newer and more lethal strains. The descriptions of smallpox death in the book I cited are the stuff of nightmares. ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [August 31, 2011, 2:44pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/28 "2011-08-31T14:44:28Z")
> [@SeaDragonTattoo](#): > > So he administered the vaccine in a butt cheek instead. I never looked around back there thoroughly enough to find the scar. This would have been about 1971. I’m sure he wasn’t the only doctor to do this, so I would bet that’s why not everyone of age to have one, doesn’t have one that’s obvious. Now that I know what it is (specifically smallpox), I’ll start sporting mine with pride. 🆒 Mine’s gone, though—it’s almost invisible now. I can feel a slight bumpiness at the injection sites, but that’s about it. ☹ I was born in ’61 and mine has always been about the size of a dime. It was quite pronounced when I was younger. I was told that soon after I was born it became more routine to stick it on an ass cheek. I know when I was a teenager a few people asked me “_dude_—what’s that thing on your arm?” Everybody who has their smallpox scar on their ass should get together, go to an anti-vax rally, and simultaneously shove them in Jenny McCarthy’s face. ---
**Author:** ![Chessic\_Sense](https://avatars.discourse-cdn.com/v4/letter/c/7c8e57/32.png) [@Chessic\_Sense](https://boards.straightdope.com/u/Chessic_Sense)\ **Post date:** [August 31, 2011, 6:35pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/29 "2011-08-31T18:35:41Z")
> [@LavenderBlue](#): > > Do they still use the smallpox in the US military? I’ve heard that they do from a friend of a friend. Yes. I got mine in 2005 and I presume nothing has changed since then. They prick you a little and then wait two or three days to see if it gets infected. If not, they prick you a lot to make sure you get it. The injection site fills with puss to a dime-sized blister. That eventually pops a week later, drains, and heals into a scar. ---
**Author:** ![irishgirl](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@irishgirl](https://boards.straightdope.com/u/irishgirl)\ **Post date:** [August 31, 2011, 7:04pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/30 "2011-08-31T19:04:36Z")
May I correct some factual inaccuracies in previous posts please? BCG is a vaccine for TB. It is given INTRADERMALLY (ID), not subcutaneously (SC) like insulin, or intramuscularly (IM) like most other vaccinations. If given correctly it will blister and scar for most people. If given too deep (IM or SC), it probably won’t work and may cause an abscess. It requires more skill than a usual vaccination to give correctly. BCG protection lasts for about 10 years, and can cause false positive reactions to TB tests. The TB test uses a skin prick- variations include [Mantoux](http://en.wikipedia.org/wiki/Mantoux_test) and [Heaf](http://en.wikipedia.org/wiki/Heaf_test). Even if positive, they won’t scar permanently. I had a BCG, which did blister and scar initially, but which has now faded and have had 3 Mantoux tests in the last 10 years. The UK has removed BCG from routine childhood immunisations schedule at age 12, instead offering it at birth to infants thought to be at risk (ethnicity, household contacts with TB, etc). Those at high risk of contracting TB through occupation etc (healthcare workers, the homeless) are offered it opportunistically. Oral polio vaccine, which uses a live vaccine, and posesa potential risk of infection with Polio to unvaccinated people handling the faeces of a recently vaccinated person (e.g. parents changing nappies, or cleaning up after a small child of potty-training age) has been replaced with injectable inactivated polio vaccines. Polio vaccination doesn’t scar. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [August 31, 2011, 10:16pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/31 "2011-08-31T22:16:54Z")
> [@Freudian\_Slit](#): > > Are you saying there’s no such thing as a TB vaccine? Because I know I’ve had it. I’ve also had the test where I tested positive because I’d already been vaccinated. It’s generally not used in the US (see above link on the topic), so I’m not surprised about the lack of awareness. ---
**Author:** ![Kiwi\_Fruit](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kiwi_fruit/32/12_2.png) [@Kiwi\_Fruit](https://boards.straightdope.com/u/Kiwi_Fruit)\ **Post date:** [August 31, 2011, 10:33pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/32 "2011-08-31T22:33:10Z")
> [@irishgirl](#): > > May I correct some factual inaccuracies in previous posts please? > > BCG is a vaccine for TB. > It is given INTRADERMALLY (ID), not subcutaneously (SC) like insulin, Thanks. I came back here to correct my incorrect assertion that the BCG vaccination was subcutaneous. ---
**Author:** ![redtail23](https://avatars.discourse-cdn.com/v4/letter/r/3e96dc/32.png) [@redtail23](https://boards.straightdope.com/u/redtail23)\ **Post date:** [September 1, 2011, 2:25am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/33 "2011-09-01T02:25:49Z")
I get TB tested yearly. They do the syringe injection thing, not a skinprick. Interestingly, they’ve never offered the vaccine as far as I’ve heard. Even though many of my co-workers are definitely at risk (direct patient care). ---
**Author:** ![irishgirl](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@irishgirl](https://boards.straightdope.com/u/irishgirl)\ **Post date:** [September 1, 2011, 4:37pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/34 "2011-09-01T16:37:12Z")
I have been offered the BCG (no scar and negative Mantoux)- I’ve declined it. My reasoning is thus: I have been exposed to plenty of TB and haven’t got it yet! I spent 4 weeks n India draining TB abscesses and giving directly observed TB therapy. If I haven’t got it yet, I’m probably not going to. My BCG did scar initially and then faded, I have no reason to believe a second one would act differently, and I might be in the same boat again in 15 years time. A new BCG would only protect me for 10 years at most. It may not even give me protection at all (some studies show 40% or more of vaccinated people get no protection from the vaccine). A new BCG could potentially confuse any future Mantoux readings. BCG offers no protection at all from the multi-drug resistant strains. As it stands I know that if I am exposed to TB and test positive it is a true positive and I can get prompt treatment. I’m OK with that, given that I now work in General Practice and see patients for 10-20 minutes at a time, minimising my risk of exposure considerably compared to hospital work. YMMV, depending on personal risk of exposure , your own level of risk-aversion and your personal comfort level dealing with medical uncertainty (i.e. I’m OK with not being vaccinated and the risk of catching TB- you might not be- in which case, get a BCG). ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [September 1, 2011, 5:55pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/35 "2011-09-01T17:55:57Z")
I got a smallpox vaccine in 2003 before I went to Iraq. They use a long tattoo-like needle and poke you in the shoulder about 10 times. Over the next week or so, a big puss-filled sore develops on the spot, which eventually turns black and heals, leaving the scar. I’m unsure why they have to do it this way as opposed to just sticking you with a syringe like most vaccines. Does anybody know if the smallpox vaccine still uses cowpox, like Jenner’s? If not, what’s the sore all about? ---
**Author:** ![Freudian\_Slit](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@Freudian\_Slit](https://boards.straightdope.com/u/Freudian_Slit)\ **Post date:** [September 1, 2011, 6:05pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/36 "2011-09-01T18:05:19Z")
> [@Ferret\_Herder](#): > > It’s generally not used in the US (see above link on the topic), so I’m not surprised about the lack of awareness. Yeah. I was in the UAE (where I spent a bit of time growing up) when I got mine. I guess most people living in the United States wouldn’t have had one. ---
**Author:** ![Ferret\_Herder](https://avatars.discourse-cdn.com/v4/letter/f/e47774/32.png) [@Ferret\_Herder](https://boards.straightdope.com/u/Ferret_Herder)\ **Post date:** [September 1, 2011, 7:17pm UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/37 "2011-09-01T19:17:16Z")
Generally, healthcare workers in the US (I’m one) undergo yearly TB testing - either blood-based or Mantoux; we use the latter where I work. I think those with positive tests (current or past) get a chest x-ray to confirm the negative status. I’ve personally known two healthcare workers (a pediatric nurse and an ophthalmic tech) who had positive Mantoux tests and had to do the x-rays. I’d rather do the blood tests. It seems like half the time I get the Mantoux, it’s not raised, but the pink color change is visible on my super-pale skin for weeks. ---
**Author:** ![Clothahump](https://avatars.discourse-cdn.com/v4/letter/c/51bf81/32.png) [@Clothahump](https://boards.straightdope.com/u/Clothahump)\ **Post date:** [September 2, 2011, 2:47am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/38 "2011-09-02T02:47:01Z")
> [@jabiru](#): > > Sabin is administered orally. Those of us who are old enough were injected with Salk vaccine. It didn’t leave a scar, though. Only memories. Yeah. I remember bawling like crazy because I was getting a shot. My mom was bawling like crazy because I wasn’t going to get polio. My sister came down with it about two years before Salk came out with the vaccine and it nearly killed her. She’s walked with a severe limp ever since. ---
**Author:** ![Freudian\_Slit](https://avatars.discourse-cdn.com/v4/letter/f/5daacb/32.png) [@Freudian\_Slit](https://boards.straightdope.com/u/Freudian_Slit)\ **Post date:** [September 2, 2011, 2:59am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/39 "2011-09-02T02:59:34Z")
> [@Ferret\_Herder](#): > > Generally, healthcare workers in the US (I’m one) undergo yearly TB testing - either blood-based or Mantoux; we use the latter where I work. I think those with positive tests (current or past) get a chest x-ray to confirm the negative status. I’ve personally known two healthcare workers (a pediatric nurse and an ophthalmic tech) who had positive Mantoux tests and had to do the x-rays. I remember as a teen having the Mantoux test as a kid. I tested positive because of my vaccine as a child but I still had to go get the x-rays done. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [September 2, 2011, 4:20am UTC](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599/40 "2011-09-02T04:20:25Z")
fascinating responses - thanks, everyone. [Previous page](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599.md?page=1) [Next page](https://boards.straightdope.com/t/why-does-the-polio-vaccine-leave-a-mark-on-the-arm/594599.md?page=3)