Immune responses in mice, cattle and horses to a DNA vaccine for vesicular stomatitis.

This research investigates the efficacy of a DNA vaccine for vesicular stomatitis virus in mice, cattle, and horses. The vaccine showed some promise in eliciting antibody response, especially with two doses, but the effect of certain co-injections was mixed.

Overview of Vesicular Stomatitis and Its Importance

• Vesicular stomatitis (VS) is a significant disease that affects cattle and horses in North America. The disease has a considerable clinical impact and poses challenges in terms of control and prevention.
• The paper emphasizes that an effective vaccine for VS needs to not only protect against the disease but also allow for the easy distinction between infected and vaccinated animals, to assist in epidemiological tracking and disease control.

Study Design and Findings

• The research evaluated the neutralizing antibody responses in mice, calves, and horses to a DNA vaccine that expressed the glycoprotein (G) gene of the VS New Jersey virus.
• The results showed that the vaccine elicited antibody titers in individuals from each of these species. Particularly, two doses of the vaccine tended to elicit stronger responses. However, the research notes that the level of neutralizing antibody required for effective protection against VS still remains unknown.
• In further analyses on mice, the researchers co-administered a plasmid expressing interleukin-2 with the DNA vaccine. This combination resulted in a significant but modest increase in antibody titers compared to using the G gene vaccine alone.
• The team also evaluated the effect of co-injecting certain purported immunostimulatory oligonucleotides with the DNA vaccine. However, these had no apparent effect in horses and even seemed to suppress the immune response to the vaccine in mice.

Implications and Future Directions

• If the immune responses observed in this study prove sufficient to protect cattle and horses from VS infection, DNA vaccination may become a helpful new tool for controlling this disease.
• This research has also identified areas for further investigation, including determining the optimal dosage and administration protocol for the DNA vaccine, understanding the most effective co-injections, and establishing the exact level of neutralizing antibodies necessary for protection against VS.