What made the 1970 German hospital smallpox case airborne versus other cases? How big or small do dust particles have to be to make variola airborne from droplet nuclei?
No one is sure why there appears to have been exceptional, apparent aerosol spread of virus in Meschede, Germany, in 1970. One must assume the index case must have been coughing out incredible amounts of virus. The observation that aerosol transmission probably occurred, was based on epidemiologic investigations that occurred after the outbreak; to be most correct, infectious aerosols were never actually experimentally demonstrated (which would have been quite difficult/impossible at the time). An important feature of this tragic event also involves the observation that despite post-exposure vaccination, a substantial number of apparently aerosol-contact patients still died. It may be noteworthy that, unlike currently accepted protocols, the potential contacts in the Meschede outbreak were first vaccinated with a non-WHO-approved local vaccine and then secondarily with WHO-approved vaccine. It is possible that this atypical, two-phased, post-exposure treatment regimen, may have contrib
