[Comparison of protective properties of the smallpox DNA-vaccine based on the variola virus A30L gene and its variant with modified codon usage].

Efficacy of candidate DNA-vaccines based on the variola virus natural gene A30L and artificial gene A30Lopt with modified codon usage, optimized for expression in mammalian cells, was tested. The groups of mice were intracutaneously immunized three times with three-week intervals with candidate DNA-vaccines: pcDNA_A30L or pcDNA_A30Lopt, and in three weeks after the last immunization all mice in the groups were intraperitoneally infected by the ectromelia virus K1 strain in 10 LD50 dose for the estimation of protection. It was shown that the DNA-vaccines based on natural gene A30L and codon-optimized gene A30Lopt elicited virus, thereby neutralizing the antibody response and protected mice from lethal intraperitoneal challenge with the ectromelia virus with lack of statistically significant difference.

[The development of method of detection of human pathogenic orthopoxviruses on the basis of polymerase chain reaction in real time].

The set of specific oligonucleotide primers and hybridization testers with the support of TaqMan in real time is proposed to identify and differentiate such human pathogenic orthopoxviruses as smallpox virus, monkey smallpox virus, cowpox virus, variolovaccine. The analytical specificity of the set is determined upon the example of 20 strains of 6 types of human pathogenic orthopoxviruses and made up 100%. The sensibility is established using recombinant plasmids containing orthopoxviruses sequence. The minimal revealed amount of plasmid made up to 20 copies for smallpox and monkey smallpox viruses, 10 copies for cowpox and 60 copies for variolovaccine in reaction.

[Development of current smallpox vaccines].

The review gives data on the history of smallpox vaccination and shows the high topicality of designing the current safe vaccines against orthopoxviruses. Four generations of live smallpox, protein subunit, and DNA vaccines are considered. Analysis of the data published leads to the conclusion that it is promising to use the up-to-date generations of safe smallpox subunit or DNA vaccines for mass primary immunization with possible further revaccination with classical live vaccine.

[Comparative analysis of variable regions in the genomes of variola virus].

Nucleotide sequences of two extended segments of the terminal variable regions in variola virus genome were determined. The size of the left segment was 13.5 kbp and of the right, 10.5 kbp. Totally, over 540 kbp were sequenced for 22 variola virus strains. The conducted phylogenetic analysis and the data published earlier allowed us to find the interrelations between 70 variola virus isolates, the character of their clustering, and the degree of intergroup and intragroup variations of the clusters of variola virus strains. The most polymorphic loci of the genome segments studied were determined. It was demonstrated that that these loci are localized to either noncoding genome regions or to the regions of destroyed open reading frames, characteristic of the ancestor virus. These loci are promising for development of the strategy for genotyping variola virus strains. Analysis of recombination using various methods demonstrated that, with the only exception, no statistically significant recombinational events in the genomes of variola virus strains studied were detectable.