Understanding Smallpox Vaccination and the Absence of Scars
A discussion on the unusual absence of smallpox vaccination scars and what it means for immunity, according to epidemiologist Prof. Pierluigi Lopalco.
Inquiries about vaccinations often arise, particularly when it comes to smallpox, a disease that has been eradicated since the late 20th century. A recent question posed to epidemiologist Prof. Pierluigi Lopalco sheds light on an unusual case regarding the absence of the typical vaccination scar.
The individual, Patrizia, recounted her experience of receiving the smallpox vaccine as a child, followed by a second vaccination at the age of 24 for a trip to Egypt. Interestingly, she noted that neither vaccination resulted in the expected round scars commonly associated with this immunization.
In his response, Prof. Lopalco explained that the presence of a scar is generally viewed as an indicator that the vaccine has successfully taken effect. The absence of such a scar could imply that the vaccine did not work, potentially due to improper administration or poor vaccine storage. However, he pointed out that it is quite rare for someone to experience this phenomenon twice, leading him to consider that Patrizia might belong to a small group of individuals who develop immunity without exhibiting any skin reactions.
Prof. Lopalco suggested that it would be scientifically interesting to check her antibody levels to confirm her immune status. He emphasized that this inquiry is purely academic, as the smallpox virus is no longer a threat due to successful vaccination campaigns.
It's important to note that smallpox vaccination was halted in Western countries starting in the 1970s. The last recorded case in the United States occurred in 1949, with vaccinations ceasing in 1972. In Italy, the vaccination program was suspended in 1977 and officially discontinued in 1981.
Prof. Pierluigi Lopalco – Epidemiologist
