BECKLEY, WV (LOOTPRESS) – Naresh Ramesh, Ph. D., is an assistant professor at WVU Tech working to solve a $500 million problem in the United States and revolutionize our perception of vaccines.
Ramesh is part of an international team researching one of the most transmitted viruses among pigs – the porcine reproductive and respiratory syndrome virus (PRRSV). According to Ramesh, PRRSV poses a significant economic risk to the pork industry and causes substantial loss of livestock globally.
“The virus is transmitted through direct contact with urine, semen (artificial insemination), and excrement. Once infected, it presents two clinical conditions: 1. reproductive impairment; 2. respiratory disease. A notable feature of PRRSV is to persist long-term as an infectious strain within carrier pigs,” Ramesh explains.
“Pigs infected by PRRSV while pregnant pose the maximum economic risk to a farm,” he said. “PRRSV infection during gestation results in increased abortions, stillbirths and weak piglets, since the virus can cross the placenta during late gestation. Healthier piglets get infected by being close to older infected pigs.”
Much of how PRRSV spreads between groups of pigs inside a farm remains poorly understood.
Industry analysts estimate the infection costs between $500 and $600 million in lost or nonviable livestock. Once a sow is infected and loses a pregnancy, the sow will likely become infertile. The meat from infected pigs is also no longer fit for human consumption.
The most frustrating part about PRRSV, Ramesh says, is how unpredictable the response the infected pigs will have to vaccination.
That is where Dr. Ramesh and a team of seven other researchers developed a new approach to dealing with the infection. He says the key could be reinforcing areas within the DNA, creating fetal resilience to PRRSV infection and vaccination.
In a previous study, researchers found a DNA region that was closely associated with healthy thyroid hormone production, called DIO2.
“This raises the question: Can we minimize fetal loss upon PRRSV infection if we create genetic variants of the DIO2 gene? This could create fetal resilience when exposed to PRRSV late in gestation and allows us to select animals resistant to or with reduced susceptibility to PRRSV,” Ramesh explains.
“In our most recently published study, we’re exploring the effect of a mutation in the DIO2 gene and fetal viability in PRRSV infection,” said Ramesh. “To our knowledge, this is the first examination that studies how a targeted gene mutation correlates with fetal viability upon infection during gestation.”
The basis of this work for dealing with PRRSV is part of a growing body of work among medical researchers. The mainstream vaccine would minimize PRRSV infection, while other agents target specific areas in the DNA that can reduce the effect of the virus and create resilience to infection. This would likely be part of the next phase in the evolution of modern immunization. Similar to how the COVID-19 mRNA vaccine works, this new PRRSV vaccine would help make the body less friendly to the virus.
Ramesh says this is one of many steps in developing new vaccines and how we think of immunization. While PRRSV has no known human carriers and the virus is currently not transmissible to humans, viruses are evolving.
“COVID-19 was originally never seen in humans at this scale until 2019. I suspect it won’t be the last,” said Ramesh. “This is the first holistic approach to viral research. While we rely on a healthy immune system and vaccination to neutralize a virus, an additional approach is to continue looking for key changes in DNA and how they impact our survival from a virus. More efforts in this area can give us a roadmap to develop targeted mutations in these regions making us resilient to infection using what we have. After all, not all mutations are bad.”
The full article is available through BMC Veterinary Research.
