File:Brazilian hemorrhagic fever07.jpeg

This 1966 photograph depicted a Brazilian mother who’d manifested the dermal lesions determined to be due to the DNA virus, variola minor, otherwise known as “alastrim”. This mother had previously received a smallpox vaccination, resulting in what was a “negative take”, and exhibited a very minor form of alastrim, while her child was convalescing from the more classical form of the disease. Rarely, in some first-time, or distantly vaccinated (re-vaccinee) individuals, seemingly appropriate vaccination techniques may result in no reaction, otherwise known as a negative-take.