Variola or Smallpox Virus. TEM X59,000 . The small pox virus is highly contagious disease among humans. It survives by passing from person to person via direct contact or inhalation of air droplets or aerosols. The majority of the population ,at least 80%, is believed to be susceptible to small pox. If the virus made it way into the general population, a major human catastrophe would occur.