An experimental vaccine to prevent chikungunya fever, a viral disease spread by certain species of mosquitoes, is being tested in a clinical trial conducted by National Institute of Allergy and Infectious Diseases (NIAID) scientists at the National Institutes of Health. The vaccine was developed by researchers at the NIAID Vaccine Research Center (VRC) using non-infectious virus-like particles to prompt an immune response. The trial is testing the vaccine’s safety and ability to elicit antibodies against chikungunya virus. It will enroll 25 healthy adults aged 18 to 50 years.
Chikungunya virus infection is generally not fatal but it can cause debilitating symptoms, most often fever, headache and severe joint pain. Symptoms usually subside in a few weeks but can last for months. The first cases of illness were reported in the early 1950s in east Africa. The disease is now endemic throughout much of Africa and parts of Asia. India, for example, has reported frequent outbreaks with significant public health impact, including a 2006 outbreak that lasted eight months and resulted in 1.25 million suspected cases of illness.
Global travel and trade have increased the risk that the disease will spread. A 2007 outbreak of chikungunya fever in Italy prompted concern that the virus is becoming established in non-tropical settings and could pose a worldwide threat. There is no specific treatment for the illness and no vaccine to prevent it.
“A vaccine to prevent chikungunya fever, an emerging global health concern, would address an important need,” said NIAID Director Anthony S. Fauci, M.D. “If successful, this approach also might be used to develop vaccines against related mosquito-borne viruses, including those that cause Western, Eastern and Venezuelan equine encephalitis.” According to the Centers for Disease Control and Prevention, human infections with these equine viruses are rare, but, in the case of Eastern equine encephalitis, more than 30 percent of infected people die and most of the survivors suffer serious neurological complications.
In 2010, scientists led by VRC Director Gary Nabel, M.D., Ph.D, reported that rhesus monkeys inoculated with the virus-like particle chikungunya vaccine 15 weeks prior to virus exposure were completely shielded from infection. Monkey blood serum containing anti-chikungunya antibodies generated by the VLP vaccine also protected immune-deficient mice from becoming infected with chikungunya virus, the scientists showed.
Date: December 20, 2011
Source: National Institute of Allergy and Infectious Diseases