When Zika virus first hit Brazil five years ago, the impact was devastating. Cases of infection with the virus began to be detected in adults in Brazil in early 2015, and then began spreading across the Americas.

But it wasn’t until the second half of 2016 that paediatricians started to see an increase in cases of microcephaly , a condition in which babies are born with a small head and sometimes brain damage, in newborns.

That year, researchers confirmed …