"High fever, delirium, vomiting, swelling of the spleen [...] on the scalp and face, then trunk, arms and legs, mucous membranes: red nodules which turn into blisters with umbilications / pock-pits and pustules. At this stage also nervous disorders and complications of the internal organs. After 12 - 14 days fever drops, regression, [...] crusts, after 3-4 weeks red scars [...] contagiosity persists for a longer period of time".
(Skin Atlas Eduard Jacobi, 1918).
The smallpox was a severe highly contagious infectious disease caused by the variola virus. Infection occurred as droplet infection, by direct contact or indirectly via contaminated objects.
After an incubation period of about two weeks, the clinical picture described above occurred, which often healed with the typical scarring. In up to 20% of the cases the normally acquired smallpox was fatal!
Similar to today's childhood diseases, smallpox could affect anyone, regardless of environment or social status: man, woman, rich, poor, peasant or king. In 1967, smallpox still posed a threat to 60% of the world's population.
Smallpox was the first infectious disease to be completely eradicated by humans. The prerequisite for this was that the smallpox virus only infects humans and that there is no other host or reservoir.
With Edward Jenner’s (1749 - 1823) technique of vaccination (inoculation of cowpox virus) a safe prevention could be carried out for the first time.
Jenner observed that peasant maids who had been infected with cowpox no longer contracted human pox. This observation led him to the hypothesis that a vaccination with cowpox would provide the same immunity as an acquired disease of cowpox and a protection against smallpox as well. After numerous experiments on humans Jenner published his results in 1798 under the title "An inquiry into the causes and effects of the variolæ vaccinæ, a disease discovered in some of the western counties of England, particularly Gloucestershire, and known by the name of the cow pox".
On 8 May 1980, during its 33rd plenary session in Geneva, WHO solemnly proclaimed that smallpox is globally eradicated. The last natural case of smallpox disease was reported from Somalia in 1977. In August 1978, a laboratory accident in Birmingham (UK) resulted in two final smallpox cases, one of which was fatal.
The eradication of smallpox was achieved thanks to the WHO's "Smallpox Eradication Programme - SEP" initiated in 1958 and intensified from 1967 onwards. Systematic monitoring, various preventive measures, vaccination campaigns, mass vaccination and international cooperation contributed to the successful fight against smallpox.