An Emergent Poxvirus from Humans and Cattle in Rio de
Janeiro State: Cantagalo Virus May Derive from Brazilian Smallpox Vaccine
This
week I felt inspired to write about another virus and found an article that
describes characteristics of a newly discover orthopoxvirus known as the
Cantagalo virus (CTGV). To provide some background before discussing the major
points of the article, the family Poxviridae
contains complex cytoplasmic DNA viruses that replicate in vertebrate and
invertebrate host and has a genus Orthopoxvirus. The human orthopoxviruses
consist of variola, monkeypox, cowpox, and vaccinia viruses (VV). The two
viruses mainly talked about from this group are the cowpox and vaccinia
viruses. The cowpox virus is a mildly disruptive disease of cows. This virus is
mostly transmitted to humans by cats. When smallpox came around in history, it
was found that milkmaids that had cowpox did not contract smallpox and the practice
of injecting healthy people with puss from the lesions of others with cowpox to
produce immunity to smallpox. The vaccinia virus is a highly effective
immunizing agent that enabled the global eradication of smallpox.
In this
study, they describe another potential established vaccinia virus, CTGV, that
was isolated from lesion samples taken during episodes of rashes that affected
dairy cattle and milkers. The results of this study indicated that CTGV is
closely related to VV-IOC, which was a smallpox vaccine strain that was
manufactured Instituto Oswaldo Cruz and used to eradicate smallpox from the
region over 20 years ago.
The interesting
and important information learned from this study began from the interpretation
of the results. Though VV-IOC and CTGV appeared to be closely related by
sequences of gene coding for certain proteins, the DNA restriction cleavage
patterns and viral proteins SDS-PAGE profiles indicated that there are several
different forms of the virus that has developed over the years. A logical reasoning
behind this could be that the virus has adopted to nature. The important information learned from this
is that this is an example of how vaccinia viruses can persist in the world.
Damaso, C.; Esposito, J.; Condit, R.; Moussatche, N.;
Virology. 2000, 277, 439-449.
It's really interesting that the vaccina viruses can adapt as the world changes. Since we know that the viruses themselves are most likely adapting and trying to find new ways to beat the vaccine, it is good to know that the vaccina virus is also changing with it. Are all or most vaccines derived from a person or being that has the infection?
ReplyDeleteVaccinia->vaccine...an etymological progression?
ReplyDelete