The firm published research showing that its F344/NHsd and Hsd:Sprague Dawley rat strains are susceptible to herpes simplex virus-2 (HSV-2) in May.
An Envigo spokesman told us “The results of this study identified that our rat models are indeed another valuable tool for researchers who are conducting HSV and vaccines studies.
“The models noted in the study had not previously been described as being useful for HSV research, so we would anticipate that customers in this field of research can now consider using these additional models to test vaccine candidates.”
Envigo also found that prior HSV-1 infection was protective against HSV-2 infection.
The research – which was conducted in collaboration with scientists at the University of Gothenburg – was prompted by the limitations of currently available mouse models and guinea pig models used to study HSV-2 infection.
These limitations – primarily the difference between the genes that regulate immune response in humans and mice and guinea pigs – prompted Envigo to test if any of the rat models it owned would be more accurate models.
The CDC estimates that 50 million people are infected by HSV-2 virus in the US. While the virus is the most common cause of genital herpes, the vast majority of infections are asymptomatic.
At present there is no vaccine against HSV-2 – a candidate Vical was developing failed to meet its primary endpoints in June last year – and treatment relies on combination antiviral therapy.
The virus is also known to play a role in HIV transmission.
Envigo sells the rat models to developers. It also uses them as part of its contract research services business.