Arizona State University has taken a major step forward in boosting Zika prevention efforts.

ASU Biodesign Institute scientist Qiang “Shawn” Chen has led his research team to develop the world’s first plant–based Zika vaccine that could be more potent, safer and cheaper to produce than any other efforts to date.

“Our vaccine offers improved safety and potentially lowers the production costs more than any other current alternative, and with equivalent effectiveness,” said Chen, a researcher in the Biodesign Center for Immunotherapy, Vaccines and Virotherapy and professor in the School of Life Sciences. “We are very excited about these results.”

Several potential Zika vaccines have had promising results in early animal and human tests. Last year, the Food and Drug Administration approved the first human testing of a Zika vaccine candidate, and this summer, a $100 million U.S. government–led clinical trial is underway.

But currently, there are no licensed vaccines or therapeutics available to combat Zika.

Several dedicated ASU scientists heeded the call to action, wanting to use their special know–how to find a way to overcome the pandemic crisis.

First, ASU chemist Alexander Green, along with collaborators at Harvard, developed a more rapid and reliable Zika test, an achievement highlighted by Popular Science in its “Best of What’s New” of 2016.

Now, Chen may have come up with a better vaccine candidate based on a key Zika protein. Chen is a viral expert who has worked for the past decade on plant–based therapeutics and vaccines against West Nile virus and dengue fever, which come from the same Zika family, called flaviviruses.

He honed in on developing a vaccine against a part of a Zika viral protein, called DIII, that plays a key role for the virus to infect people.

“All flaviviruses have the envelope protein on the outside part of the virus. It has three domains. The domain III has a unique stretch of DNA for the Zika virus, and we exploited this to generate a robust and protective immune response that is unique for Zika,” Chen said.

They first grew the envelope protein in bacteria, then switched to prepare the DIII protein domain in tobacco plants.

After developing enough material for the new vaccine candidate, Chen’s team performed immunization experiments in mice, which induced antibody and cellular immune responses that have been shown to confer 100 percent protection against multiple Zika virus strains in a mouse challenge.

Producing plant–based vaccines, especially in tobacco plants, is old hat for ASU researchers like Chen. For more than a decade, they’ve been producing low–cost vaccines in plants to fight devastating infectious diseases in the developing world.

It’s the same approach ASU plant research pioneer Charles Arntzen used when he played a key role in developing ZMapp, the experimental treatment used during the Ebola outbreak.

The research was published in the journal Scientific Reports.