Poxviridae

History:

• 1200 B.C. small pox killed pharaoh Ramses V.
• Spanish decimated the Aztecs in the 16th century.
• Edward Jenner found a vaccination for smallpox in 1796.
• WHO vaccination program in 1950. WHO declared small pox eradicated in 1980

Structure of viruses and its classification:

• Smallpox and vaccinia belongs to a group of viruses called orthopoxvirus.
  
• Largest family of viruses.
• has a unique oval shape.
• Antigenically complex.
• can remain stable in air for hours.
• linear dsDNA.

Viral disease and host defense:

• can attack humans only.
• can be spread by respiratory secretions.
• always associated with skin lesions.
• at least 9 pox viruses cause disease in humans.
  
• 12-7 days of incubation.
• influenza-like symptoms initially .
• characteristics pustules.
• scarring of skins.
• neurological damage.
• blindness
• death

Molecular biology research and viral therapy:

• Edward Jenner was the one that found the vaccination for small pox. he used cowpox from milkmaids and vaccinated 8 year old James Phipps. he then challenged smallpox.
• vaccinia can be evolved from cowpox or smallpox. they can also be used as a vector.
• smallpox can be eradicated because there is no other reservoir for the virus other than humans.
• the virus causes only acute infection from which the patients dies, or he obtains lifelong immunity.
• the virus is also an effective immunogen.
• the virus is not infectious during incubation but during its symptoms.
• it can be spread by aerosol or air droplets.
  
• best defense is vaccination.

Other uses of poxviridae:

• smallpox is used by terrorists to cause an outbreak in countries that they intend to terrorize.