 | Smallpox virus, growing in the cytoplasm of an infected cell. Thin section of infected chick embryo cell. Mature virions are brick-shaped, but here immature forms are also visible. Smallpox virus was globally eradicated in 1977 by an international vaccination campaign, one of the greatest achievements in history. Magnification approximately x25,000. Micrograph from F. A. Murphy, University of Texas Medical Branch, Galveston, Texas. Download TIF for Image 1 |