The single mutation was found during a recent study.
Researchers suggest this could trigger another major outbreak of the disease by dodging existing immunity.
Dr. Pei-Yong Shi, a professor at the Department of Biochemistry and Molecular Biology at UTMB Galveston, says the virus is carried by the bite of infected mosquitoes.
He says the virus can be especially harmful to pregnant women since the infection can cause certain birth defects.
"The most devastating outcome of Zika infection is called microcephaly which is the pregnant woman got infected by a mosquito," said Shi.
"That virus can infect the fetus' brain, leading to the baby (being) born with a small head."
Shi says this study measures mosquitoes that transmit Zika and other viruses such as the Dengue virus which tends to co-circulate in the same places.
"Previous studies have shown that people who have been infected by Dengue are partially protected from Zika infection because of the gene similarities between the two viruses," Shi said.
"What we did is test when the Zika virus will be able to escape the protection previously triggered by the dengue infection. What we found remarkable is that the Zika virus can accumulate a single amino acid mutation that is going to override all the protections previously triggered by dengue infection," he continued.
Shi says there's currently no cure for Zika. He says Zika-infected patients can develop Guillain Barre Syndrome, which is the autoimmune disease that can cause paralysis.
According to Shi, "There is still no vaccine. No therapeutics for Zika, so the whole human population is very vulnerable."