New vaccine regimen shows promise against Chikungunya virus

Researchers, including one of Indian-origin, have developed a novel vaccine regimen that produces rapid and long-term protection against Chikungunya virus (CHIKV) that is transmitted through mosquitoes and causes fever and joint pain that can sometimes become severe and disabling.

Outbreaks of the virus have already occurred in Asia, Africa and Europe, and, in late 2013, the virus was first seen in the Americas with the number of cases dramatically increased.

No vaccine to prevent or treat this virus currently exists, the study pointed out.

"The vaccination regimen we tested in this study provided stable, persistent responses against a virus with rapidly increasing global incidence," said first author of the study Karrupiah Muthumani, assistant professor at The Wistar Institute in Philadelphia, US.

"This new approach will likely have importance for a variety of infectious and non-infectious diseases," Muthumani noted.

The study, published in the Journal of Infectious Diseases, showed how the vaccine strategy that boosts the immune system by rapidly producing antibodies against CHIKV, combined with a traditional DNA-based vaccine approach, can provide both short term and long term protection against the virus.

"Antigen-based vaccination strategies require a lag time that leaves patients susceptible to infection and disease," senior author of the study David Weiner from The Wistar Institute said.

"This novel strategy for generating rapid immune protection has the ability to fill this gap in the way vaccines are developed for CHIKV and other emerging and dangerous diseases," Weiner noted.

In this study, when mice infected with CHIKV were given one intramuscular injection of the monoclonal antibody-producing CHIKV vaccine, antibodies against the virus were generated in vivo within 24 hours of administration.

The injection neutralised isolated pockets of the virus and protected the mice from viral challenge.

Since the virus usually manifests itself within three-to-seven days of transmission, a rapid response is important for reducing the burden of the disease.

When combined with a DNA-based vaccine for CHIKV, the researchers observed both rapid and long-lived protection against the virus.