Breakthrough in Dengue Virus Research

by Hannah Punitha on Jul 23 2008 7:57 PM

In a breakthrough study, scientists at Maryland and South Carolina have come up with a novel four-component vaccine that has shown success against all four strains of the dengue virus in monkeys.

The new vaccine also holds potential to offer protection to the millions of humans at risk worldwide.

There are four distinct but similar strains of dengue virus causing more than 100 million annual infections worldwide. The virus mainly puts at risk tropical regions where illness may range from mild symptoms to potentially fatal forms of dengue hemorrhagic fever and dengue shock syndrome.

And as all four strains of the virus share similar clinical presentation, epidemiology, and distribution, development of a vaccine offering multi-faceted protection has become a global health priority.

But now, researchers have developed a tetravalent dengue virus vaccine by combining genes and proteins from all four dengue virus types as well as incorporating an adenovirus agent.

After the intramuscular vaccination, rhesus macaques showed high antibody levels that neutralized all four of the dengue virus types.

For further testing the sustainability of the protective immune response, two separate live-virus challenges were administered at 4 and 24 weeks after the final inoculation. Results showed complete protection against dengue types 1 and 3 and significant protection against types 2 and 4.

"Results reported here demonstrate that the tetravalent dengue vaccine elicited a neutralizing antibody response to all four dengue virus stereotypes and provided both short-term and long-term protection against challenges from each of the four serotypes," said the researchers.

The findings of the study are reported in the latest issue of the Journal of Virology.