You’ve probably noticed that some people have a small round scar on their upper. That is the scar from being vaccinated for small pox. This smallpox vaccine was common before 1970s. Doctors used a live Vaccinia virus so that they could trigger an immune response that would protect people against the dangerous Variola virus that caused smallpox.
Blisters form at the vaccination area after the vaccination. At first, they became crusted over, but healed in several weeks. A round scar was left in the end.
Doctors used a bifurcated needle which was dipped into the Vaccinia solution to deliver the vaccine, and the individual’s arm was poked several times. Each time the needle broke the skin, a small amount of the vaccine was deposited and blisters formed, so this probably explains why the scars are so large.
Right after the application of the vaccine, a small swelling appears at the vaccination site which persists for 6-8 hours. Then, the swelling disappears and the vaccination site looks normal. 6-8 weeks later a swelling appears once again and it looks like a mosquito bite. It then starts to grow and forms a nodule which breaks open and discharges some fluid and forms an ulcer. The ulcer heals by forming a scar. This entire process takes 2-5 weeks. Sometimes, this process of ulceration and healing recurs 2-3 times. The formed scar remains forever.
Smallpox was no longer present in most of the Western world after the early 1970’s, so vaccination wasn’t needed unless a person was travelling to a country where the virus was still present.
In 1980’s, the Variola virus was certified to have been eradicated from the world’s population. This smallpox vaccination was stopped completely.