A small mutation can potentially make the Zika virus more infectious and better able to avoid pre-existing immunity, according to peer reviewed research published Tuesday in Cell Reports, underscoring the lingering risks from a virus that swept through Latin America in 2015, kicked off a global health crisis and left thousands of children to be born with birth defects and brain damage.
Zika mutates rapidly as it moves back and forth between its human hosts and mosquitos, a cycle the researchers mimicked by repeatedly switching the virus between mosquito and mice cells to see how many mutations would change the virus’ behavior.
Changing just one amino acid—a type of chemical that’s vital for life and are the building blocks used to make proteins—allowed the Zika virus to make more copies of itself and help infections take hold more easily, the researchers found, with increased virus replication in human, mosquito and mice cells.
A high replication rate in either mosquitoes or humans “could increase viral transmission or pathogenicity—and cause a new outbreak,” said the study’s first author Dr. Jose Angel Regla-Nava, an associate professor at the University of Guadalajara, Mexico.
The mutant variant could also escape the protection against Zika that follows infection with dengue, a distinct but biologically similar virus, the researchers said, based on experiments in mice.
If the Zika variant becomes prevalent in humans, we may face a similar issue with immunity, warned study co-lead Professor Sujan Shresta, a viral immunologist at the La Jolla Institute for Immunology.
Shresta and the other researchers are already exploring ways to adapt any future Zika vaccines and treatments to counteract the dangerous mutation and hope that gaining a better understanding of how the mutation helps the virus replicate more efficiently will make a difference.
Carried on the wings of mosquitoes, an obscure virus first discovered in Uganda’s Zika forest in 1947 swept through the Americas and sparked a global health panic in 2015. While the virus causes no or only mild symptoms for the majority of adults catching it, it can trigger serious birth defects if infecting someone who is pregnant. The outbreak upended travel and prompted officials to implore people to put off having kids. The disease even spread within the continental U.S., sickening more than 200 people in Florida and Texas and affecting thousands more traveling and in U.S. territories, according to CDC data. The agency says there have been no confirmed reports of Zika virus disease in U.S. territories since 2019. The World Health Organization says a total of 86 countries and territories have reported evidence of mosquito-borne Zika infection. Despite ongoing efforts, there is currently no vaccine for the virus.
What To Watch For
The next pandemic. Experts believe the next pandemic might be caused by a virus like Zika. In late March, Dr. Sylvie Briand, director of the global infectious hazard preparedness team at the WHO, said the next pandemic would “very likely” be caused by a group of pathogens called arboviruses, which are spread by arthropods like ticks and mosquitoes. The family includes Zika, yellow fever, Chikungunya and dengue and are already a significant public health problem in many tropical regions. “We also have some signals that the risk is increasing,” Briand said, pointing to growing rates of dengue and yellow fever since 2000.