The mosquito-borne Zika virus is a single mutation away from becoming more infectious and harmful, scientists say.
There is no vaccine for Zika but symptoms often don’t develop or are mild such as a fever, rash and conjunctivitis. However, it can cause birth defects such as microcephaly, where a child is born with a small head and often a smaller brain. Rarely, it can affect the nervous system through Guillain-Barre syndrome.
Scientists in California mimicked how it could mutate in humans by switching the virus back and forth between mosquito and mouse cells.