The isolation of presumptive hybrids from the viruses of variola major and cowpox has already been described (Dumbell & Bedson, 1964). We report here the detailed characterization of the 16 clones of virus obtained. As with the alastrimrabbit pox hybrids considered in the previous paper (Bedson & Dumbell, 1964), attention has been paid to the behaviour of the ceiling temperature character in re...

This Memorandum discusses the fate of variola virus stocks which have been kept in two WHO Collaborating Centres, as well as cloned DNA fragments of variola virus genome, smallpox vaccine, and seed vaccinia virus for the production of this vaccine. General and specific recommendations are given concerning destruction of variola virus; storage, distribution and handling of cloned DNA fragments o...

Variola major virus, the causative agent of smallpox, encodes the dual-specificity H1 phosphatase. Because this enzyme is essential for the production of mature virus particles, it is an attractive molecular target for the development of therapeutic countermeasures for this potential agent of bioterrorism. As a first step in this direction, the crystal structure of H1 phosphatase has been deter...

Variola minor 38 Clinical course 38 Variola sine eruptione and subclinical infection 40 Smallpox acquired by unusual routes of infection 40 Inoculation variola and variolation 40 Congenital smallpox 42 Effects of vaccination on the clinical course of smallpox 42 Effects of vaccination on toxaemia 43 Effects of vaccination on the number of lesions 43 Effects of vaccination on the character and e...

Human disease likely attributable to variola virus (VARV), the etiologic agent of smallpox, has been reported in human populations for >2,000 years. VARV is unique among orthopoxviruses in that it is an exclusively human pathogen. Because VARV has a large, slowly evolving DNA genome, we were able to construct a robust phylogeny of VARV by analyzing concatenated single nucleotide polymorphisms (...

Smallpox, once a devastating disease caused by Variola virus, a member of the Orthopoxvirus genus, was eradicated in 1980. However, the importance of variola virus infections has been stressed widely in the last few years, particularly following recent social events in the world. Today, variola virus is considered to be one of the most significant agents with potential use as a biological weapo...

A novel reagentless direct electrochemical DNA sensor has been developed using ultrathin films of the conducting polymer polypyrrole doped with an oligonucleotide probe. Our goal was to develop a prototype electrochemical DNA sensor for detection of a biowarfare pathogen, variola major virus. The sensor has been optimized for higher specificity and sensitivity. It was possible to detect 1.6 fmo...