Variola Virus

Variola virus is a double-stranded DNA virus that causes smallpox. Because the virus only infects humans, smallpox was able to be eradicated. Transmission of Variola can happen in one of several ways, including face-to-face contact, direct contact with contaminated objects, or through the air. Because of the hazards associated with exposure to this virus, scientists have not studied it fully.

Smallpox Disease

What Is Variola Virus?

Variola virus is the virus that causes smallpox. This is a double-stranded DNA virus in the family Poxviridae and the genus Orthopoxvirus.

This virus only infects humans, which is the main reason why it was able to be eradicated.

History of the Virus

Variola virus infections were described in Asia during the 1st century, in Europe and Africa around 700 A.D., and in Central, South, and North America during the 16th and 17th centuries.

According to some health experts, these infections are responsible for more deaths than all other infectious diseases combined over the centuries.

Thanks to the success of a worldwide vaccination program, smallpox has been eradicated. The last naturally occurring case in the world was in Somalia in 1977. In 1980, the World Health Organization (WHO) officially said that smallpox was wiped out worldwide, and no cases of naturally occurring smallpox have happened since.

After variola virus was eliminated from the world, routine vaccination against smallpox among the general public was stopped because it was no longer considered necessary for prevention.

Transmitting the Variola Virus

Variola virus transmission can happen in one of several ways:

Face-to-face contact
Direct contact with infected fluids and contaminated objects
Through the air.

When the virus enters the body, it spreads within the bloodstream to small blood vessels in the skin. After 7 to 17 days, smallpox symptoms will begin.

(Click Smallpox Transmission for more information.)

(Variola Virus Continued: Page 2)