As the CDC issues travel warnings for Miami, Florida, the National Institutes of Health are set to begin the first human trials for an experimental vaccine for Zika. Last week, Florida health officials identified four cases of the Zika virus that were likely transmitted by mosquitoes, which will make efforts to combat the illness even more difficult.

The first human trials for the vaccine will take place in Maryland and Georgia, according to Technology Review, and will involve 80 people in four study groups who will be injected with the vaccine and monitored for the next two years. Earlier this year, the DNA vaccine was proven to be effective in mice.

The vaccine in question is called a DNA Vaccine, a third-generation vaccine that contains some specific antigens from the disease in question. The host body will pick up the DNA from the pathogen and begin to formulate an immune response. This type of vaccine is different from others, which utilize weakened or dead germs to stimulate a response (such as for polio or smallpox) or a subunit of a pathogen.

Currently, no third generation vaccines are approved for human use in the US

Currently, there aren’t any such vaccines that can be used on people in the United States, although Australia permits the use of one for Japanese encephalitis, another mosquito-borne illness. According to the National Institutes of Health, this Zika vaccine is similar to another third-generation vaccine trial that had been developed for the West Nile Virus, which was demonstrated to be safe.

There are other vaccines on the way: experimental trial from Inovio Pharmaceuticals was approved for human trials earlier this year. However, while new vaccines will be a welcome tool in the fight against Zika, they will be just one tool that can be used to control the spread of the illness. The Maryland trial will last for up to two years, and it could be years before it could be ready for wide-spread usage. Control methods such as spraying for mosquitoes, travel advisories, and proper protection will help reduce exposure to the virus and will help limit its adverse affects.