Scientists report world's first Zika virus clone

US researchers said Monday they have, for the first time ever, succeeded in genetically engineering a clone of the Zika virus strain that is currently spreading in the Americas.

The research, published in the U.S. journal Cell Host and Microbe, could help speed up vaccine and therapeutics development for the mosquito-borne virus, researchers from the University of Texas Medical Branch (UTMB) said.

In the study, the UTMB team, led by Professor Pei-Yong Shi, first individually cloned five genome fragments and then assembled them together to form the Zika virus clone.

The researchers then used the Zika mouse model, developed by the university itself, to demonstrate that the cloned virus infected the mice and gave them neurological disease.

The team also fed Aedes aegypti mosquitoes, one of the mosquito types known to transmit Zika, with human blood infected with either the parental Zika virus or the "man-made" Zika virus and found that the number of infected mosquitoes was similar.

A number of possible factors that may account for the current Zika virus epidemic that can now be tested with the "man-made" virus, they said.

For instance, the Zika virus may have evolved in a way that enhances mosquito transmission, leading to it spreading much more quickly.

This idea could be tested by comparing how infectious the original Zika strains are to mosquitos with current strains, followed by manipulating the clone to test the effects of recent mutations on mosquito transmission.

"The new Zika clone, together with mosquito infection models and the UTMB-developed Zika mouse model, represent a major advance towards deciphering why the virus is tied to serious diseases," said Shi.

"The new clone is also a critical step in developing a vaccine and antiviral drug against Zika," he added.