translation.en: Smallpox was a systemic disease, officially eradicated since 1979, caused by infection with the Variola major virus, whose only reservoir was infected humans.
translation.lv: Bakas bija sistēmas slimība, kas ir oficiāli izskausta kopš 1979. gada. Tās izraisīja infekcija ar vīrusu Variola major, kura vienīgais rezervuārs bija inficēti cilvēki.