One mutation is already rapidly evolving Zika virus Scientists have warned that another major spread of the disease could be caused by avoiding existing immunity.
The ZikavirusWhich is carried MosquitoesIt is usually mild in adults, however it can infect the developing fetus and cause congenital defects such as MicrocephalyCausing infants to have reduced head size and symptoms, including developmental delays, seizures, and delayed speech ability.
In severe cases it can cause fatal brain damage in infants and miscarriage or stillbirth in pregnant women, while its prevalence in America in 2015 and 2016 caused a global alarm.
Now, researchers at the La Jolla Institute of Immunology (LJI) in California have found that the virus can easily mutate and become more infectious with a single change of amino acid.
In a virus that is already showing signs of rapid evolution, scientists fear it could allow infections to spread more widely, says their article, which was published in Cell Reports.
They found that a dangerous mutation (called NS2B I39V / I39T) enhances the ability of the virus to multiply in mice, mosquitoes and human cells.
Zika has many of the same biological properties as the dengue virus, and earlier exposure to dengue can protect Zika. However, the researchers said that both viruses mutate rapidly and the emerging virus means that long-term protection is not guaranteed.
“Dengue and Zika are RNA viruses, which means they can alter the genome,” said Professor Sujan Shresta, who led the study with a team from the University of Texas Medical Branch.
“When there are so many mosquitoes and so many human hosts, these viruses are constantly moving back and forth and evolving.
“The Zika variant we have identified has evolved to the point where the cross-protective immunity bestowed by previous dengue infections was no longer effective in mice.
Unfortunately for us, if this option spreads, we could have the same problems in real life.
Jose Angel Regla-Nava, a former LJI researcher and current associate professor at the University of Guadalajara, Mexico, said: “This single mutation is enough to increase the virulence of the Zika virus.
“High rates of multiplication in mosquitoes or human hosts may increase virus transmission or pathogenicity and lead to new epidemics.”