Wait, does everyone have this very same scar? People are only just realising where it comes from

Loads of tweets are going viral at the moment, attaching the same picture of a scar or mark, and asking if other people have noticed they have the same thing. So now, I’m wondering what the hell is going on. 

If you do have the scar, you might already know. And if you don’t, you’re probably wondering what on earth is going on. “Can anyone explain why everyone has this mark?” one post said. Another added: “Why does this old vaccine leave a permanent circular scar? Can you explain the science?”

Can anyone explain why everyone has this mark? pic.twitter.com/lFYn8nL6pp

— Jessica M (@Jesii_ca_M) August 9, 2026

whyy does this old vaccine leave a permanent circular scar?
@grok can you explain the science? pic.twitter.com/SHH1d7eTaq

— rain☔ (@Rainonnmeee) August 9, 2026

That post gave at least some of the answer away, so here’s it fully explained. 

So, why do so many people have this same scar and where does it come from? 

Most Read

The Lion King composer ordered to pay comedian after $27m lawsuit over podcast joke backfires

He’s not in Death of the Pastor’s Wife, so where is Mica Miller’s first husband Jeremy Deas now?

Ralph Fiennes isn’t returning as Voldemort in Harry Potter, but here’s what he actually said

The posts that are going viral all contain a picture of a circle scar or mark, at the top of someone’s arm. It seems to have quite an obvious centre, and creates tiny ridges in the skin. All in all, it’s a very recognisable mark. 

The scar is left on the skin from the Bacille Calmette-Guérin BCG vaccine (that protects against TB) or old smallpox vaccine. Both deliver live attenuated microbes into the skin. They trigger a controlled local infection.

As it then heals over the coming weeks to months, normal skin is replaced by dense, disorganised collagen scar tissue that remains permanent. So, lots of people have this identical, permanent scar tissue on their arms. 

Not the immigrant scar…. https://t.co/M7aykY9fWQ

— K̷a̷̷r̷̷e̷̷n̷a̷ ❤️ (@karenaaaax) September 1, 2025

Other people have noticed lots of celebrities have it, and have called it the “immigrant scar”. An “immigrant scar” is a colloquial term, often used to describe the round, pitted scar on the upper arm that results from childhood vaccinations, such as the BCG vaccine or an older smallpox vaccine.

The reason it’s nicknamed that is because not everyone in all countries is required to get the jabs. Routine smallpox vaccination in the UK ended in 1971. 

For more like this, like The Tab on Facebook.