Over 3,000 years ago, one of the most devastating diseases known to humanity began it’s path of destruction. A member of the orthopoxvirus family, a double-stranded DNA virus by the name variola major.
Variola major usually enters through the respiratory tract. It attaches to the mouth, trachea or lung mucosa. The cells of your mucous membranes are not tightly packed allowing the virus to penetrate and move into the saliva. Following attachment to cell surfaces and fusion with the plasma or endosomal membrane, viral replication is initiated by entry of the viral core into the cytoplasm, where all subsequent steps of the life cycle take place.
Variola virion cores harbor the viral DNA-dependent RNA polymerase and transcription factors necessary for expression of early genes, which constitute nearly half of the viral genome and encode proteins needed for DNA replication and intermediate gene transcription, as well as a large number of immunomodulators.
Variola exhibits a temporally-regulated gene expression program, i.e., expression of early genes encoding DNA replication and intermediate transcription factors triggers the expression of intermediate genes encoding late gene specific transcription factors. Late gene products primarily consist of structural proteins needed for progeny virion assembly, as well as those enzymes destined for incorporation into progeny virions.
Assembly of the mature virion or “individual viral particle” involves more than 80 viral gene products. In addition, during transit through the cytoplasm, a subset of progeny mature virions acquires two additional membrane bilayers, one of which is lost during exocytosis of the particle, to yield the less abundant enveloped virion.
It has been estimated that variola major was responsible for about 300-500 million deaths during the 20th century. During the early 1950s an estimated 50 million cases occurred in the world each year. As recently as 1967, the World Health Organization estimated that 15 million people contracted the disease and that 2 million died in that year.
So what is the common name for the Variola Major virus? Smallpox.
Smallpox is a horrifically painful disease. The “pox” small pustules filled with liquid, which have given the disease its name, usually broke out six days after the patient got sick. They initially appeared on the forehead and wrists and spread as open sores in the mouth and throat.
Within 24 hours the pox often covered the entire body of a patient.
Eventually the liquid in the pustules changed from clear to an opaque yellow pus and the pustules rose to a size of up to a half centimetre above the skin. Some were so stricken that the pox merged into what looked like a single yellow pustule. Smallpox patients suffered from excruciating pain describing pain under each pustule as though BBs were embedded under the surface of every inch of their skin.
Pustules and skin infections beneath facial skin could rendered patients unrecognizable. When pregnant women contracted the disease they usually miscarried. Another common complication was encephalomyelitis, an acute inflammation of the spinal cord and brain. Not to mention pulmonary infections, inner ear infections, other skin infections, gangrene, paralyses and heart failures. It’s hard to say which of these symptoms and maladies would be the final cause of death for the unfortunate victims – probably a cocktail of them all.
Those who survived Smallpox were horrifically scarred with pockmarks, particularly all over the face. Many patients were left blind in one or both eyes after their bodies were rid of the virus.
Queen Elizabeth I of England covered her smallpox scars, or pockmarks, with a thick coat of ghostly white make up powder. This was an attempt at covering her pockmarks, not a fashion statement.
After successful vaccination campaigns throughout the 19th and 20th centuries, the WHO certified the eradication of smallpox in December 1979.
To this day, smallpox is the only human infectious disease to have been completely eradicated.
Vaccines save lives.