Following the eradication of smallpox, scientists and public health officials determined there was still a need to perform research using the variola virus. They agreed to reduce the number of laboratories holding stocks of variola virus to only four locations. In 1981, the four countries that either served as a WHO collaborating center or were actively working with variola virus were the United States, England, Russia, and South Africa. By 1984, England and South Africa had either destroyed their stocks or transferred them to other approved labs. There are now only two locations where variola virus is officially stored and handled under WHO supervision: the Centers for Disease Control and Prevention in Atlanta, Georgia, and the State Research Center of Virology and Biotechnology (VECTOR Institute) in Koltsovo, Russia.