From Wikipedia: Tetralogy of Fallot (TOF) is a congenital heart defect which is classically understood to involve four anatomical abnormalities (although only three of them are always present). It is the most common cyanotic heart defect, representing 55-70%, and the most common cause of blue baby syndrome..
Variola (the virus that causes smallpox) is a member of the orthopoxvirus genus, which also includes viruses that cause cowpox, monkeypox, orf, and molluscum contagiosum. Poxviruses are the largest animal viruses, visible with a light microscope.They are larger than some bacteria and contain double-stranded DNA. Poxviruses are the only viruses that do not need a cell's nucleus to replicate inside the cell. The variola virus is the only known cause of smallpox.The disease affects only humans.oxviruses are the only viruses that do not need a cell's nucleus to replicate inside the cell. The variola virus is the only known cause of smallpox. The disease affects only humans.
The only other choice is prevention through the use of the vaccine (Mayo, 2002). The smallpox vaccine is a live vaccine, derived from the vaccinia virus. The vaccine does not contain or cause a variola infection.It provides an individual with immunity for 3 to 5 years, which decreases from after that period of time. The vaccine has provided protection to 95% of the vaccinated individuals.n infection of the variola virus starts out with flu-like symptoms, then rashes and scabs form throughout  similar to chickenpox, eventually in fatal cases, leading to malignant diseases such as intravascular coagulation, hypotention, cardiovascular collapse or bleeding of skin and intestinal tract (IOM, 1999).