Eastern equine encephalitis virus (EEEV), Western equine encephalitis (WEEV), Venezuelan equine encephalitis (VEEV) are all viruses causing rare infections that are spread from mosquitoes to humans. So rare, in fact, that the United States records only about 11 cases each year. Horses, while unable to spread the infection to humans, can also be infected by these viruses.
While rare in humans, these infections can be deadly. In most cases, the viruses cause flu-like symptoms. There isn’t a specific treatment used beside letting the body fight the virus. In severe cases, however, neurological damage or death can occur. Because of these potentially fatal risks, the virus can be more dangerous for people in certain situations where the chances of contracting the virus are higher, such as military personnel.
To make matters worse, under certain circumstances, these viruses can be manipulated to spread through the air, making them biological agents requiring close scrutiny from a national security perspective. The National Institutes of Allergy and Infectious Diseases (NIAID) is addressing this risk, in the form of a vaccine. Their work is presented in a recent paper published in Lancet Infectious Diseases.
The vaccine developed by NIAID researchers is a virus-like particle vaccine. This type of vaccine uses materials that look just like the virus the vaccine is designed to protect against. However, these virus look-alikes do not have the genetic material needed to replicate. The virus-like particles also have proteins on their surfaces similar to proteins on EEEV, WEEV, and VEEV, which is designed to elicit a response from the immune system.
The Phase 1 trial to test the vaccine's initial safety showed some promising results. Thirty volunteers between the ages of 18 and 50 received a dose of the vaccines through an injection, and then a booster dose about eight weeks later. Overall, the vaccine appeared to be safe, was tolerated well by participants, and generated an immune response in the form of neutralizing antibodies.
The evidence suggests that the vaccine should be further studied in clinical trials.