GM mosquitoes immune to all strains of dengue virus created

Scientists have for the first time genetically engineered mosquitoes that are resistant to all strains of the potentially deadly dengue virus.

Researchers at the University of California - San Diego, and Vanderbilt University in the US identified a broad spectrum human antibody for dengue suppression.

Described in the journal PLOS Pathogens, the research marks the first engineered approach in mosquitoes that targets the four known types of dengue, improving upon previous designs that addressed single strains.

They then designed the antibody "cargo" to be synthetically expressed in female Aedes aegypti mosquitoes, which spread the dengue virus.

"Once the female mosquito takes in blood, the antibody is activated and expressed -- that's the trigger," said UC San Diego Associate Professor Omar Akbari.

"The antibody is able to hinder the replication of the virus and prevent its dissemination throughout the mosquito, which then prevents its transmission to humans. It's a powerful approach," Akbari said in a statement.

The engineered mosquitoes could easily be paired with a dissemination system capable of spreading the antibody throughout wild disease-transmitting mosquito populations.

"It is fascinating that we now can transfer genes from the human immune system to confer immunity to mosquitoes.

"This work opens up a whole new field of biotechnology possibilities to interrupt mosquito-borne diseases of man," said James Crowe, director of the Vanderbilt Vaccine Center at Vanderbilt University.

According to the World Health Organization (WHO), dengue virus threatens millions of people in tropical and sub-tropical climates.

Severe dengue is a leading cause of serious illness and death among children in many Asian and Latin American countries.

Infecting those with compromised immune systems, dengue victims suffer flu-like symptoms, including severe fevers and rashes.

Serious cases can include life-threatening bleeding, the researchers said.

Currently no specific treatment exists, and thus prevention and control depend on measures that stop the spread of the virus, they said.

"This development means that in the foreseeable future there may be viable genetic approaches to controlling dengue virus in the field, which could limit human suffering and mortality," said Akbari.

His lab is now in the early stages of testing methods to simultaneously neutralise mosquitoes against dengue and a suite of other viruses such as Zika, yellow fever and chikungunya.