Why does the smallpox vaccine leave a scar?

The smallpox vaccine actually contained a strain of cowpox (vaccinia), not smallpox (variola). The vaccination causes causes the small scar (less than 1 cm diameter), that is evidence that the person has been properly vaccinated. A case of smallpox by comparison, was quite alarming and often fatal. read more

Both vaccine types can leave upper arm scars. Often, a person can tell the difference between the smallpox vaccine and BCG scars by taking into account the following considerations: The smallpox vaccine was not widely distributed in the United States after 1972. If a person was born after this time, their vaccine scar is likely a BCG scar. read more

When smallpox vaccine is injected to the skin using a needle with several fork-like branches, the body would have some reactions, causing sickness or antibodies to form. When the injected spot recovers, a scar would form. What You Should Know About Smallpox Vaccine. The smallpox vaccine consists of a mild cousin of the variola live virus called vaccinia. read more