Abstract
Vaccinia Virus (VACV) was widely used in smallpox vaccines in Brazil during the world vaccination campaign of Word Health Organization. After ends of this campaign in Brazil in 1980, zoonotic Vaccinia outbreaks have been recorded in several regions of the country. Researches believed that the VACV used in the word vaccination campaign in Brazil was involved in the re-emergence of the disease. To analyze the similarity between the viruses isolated from outbreaks and those used during Smallpox eradication, phylogenetic analyzes of vaccines viruses were compared to VACV isolated in outbreaks, and the result obtained was that Brazilians VACV are not grouped with vaccines viruses. The origin of outbreaks remains unknown in Brazil, but the most accepted theory assumes that there is populations of VACV genetically diverse circulating in still unknown natural reservoirs, and according on biological and geographical conditions are transmitted to cows and human beings. There is little information about natural reservoirs of VACV. It is believed that some species of Rodent Order act as VACV natural reservoirs. Although, studies have demonstrated the possible of transmission of VACV from mice experimentally infected to cow, this interaction has not yet been proven in natural environment. There are two genetically distinct groups of VACV circulating in Brazil. Experimentally these two groups also differ biologically, but no difference in clinical signs was observed during outbreaks. This review analyzed VACV natural history and epidemiological studies conducted in the last years in Brazil.
Highlights
Vaccinia Virus (VACV), the prototype of Orthopoxvirus, was widely used in Smallpox vaccines in Brazil during the world vaccination campaign of Word Health Organization [1]
The origin of outbreaks remains unknown in Brazil, but the most accepted theory assumes that there is a populations of VACV genetically diverse circulating in still unknown natural reservoirs, and according on biological and geographical conditions are transmitted to cows and human beings [14,15,16]
Aiming to analyze the similarity between the viruses isolated over the years in Brazil and those used during Smallpox eradication, phylogenetic analyzes of vaccines viruses were compared to VACV isolated in outbreaks, and the result obtained was that Brazilians VACV are not grouped with vaccines viruses, making it clear that the natural history of VACV is distinct from the vaccine viruses used in Brazil [11,15]
Summary
Vaccinia Virus (VACV), the prototype of Orthopoxvirus, was widely used in Smallpox vaccines in Brazil during the world vaccination campaign of Word Health Organization [1]. The finds of Edwar Jenner was later named immunological crossreaction of Orthopoxvirus genus [3] These Orthopoxvirus properties allow the use of VACV in Smallpox vaccines. The origin of outbreaks remains unknown in Brazil, but the most accepted theory assumes that there is a populations of VACV genetically diverse circulating in still unknown natural reservoirs, and according on biological and geographical conditions are transmitted to cows and human beings [14,15,16]. Studies has demonstrated the possible of transmission of VACV from mice experimentally infected to cow [4,19,20] This interaction has not yet been proven in natural environment. VACV outbreaks affecting other mammals species beyond cows was described in Brazil. Molecular analysis of VACV isolated in this outbreak shows two distinct VACV viruses.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
