We are a step closer to understanding how the Zika virus harms humans, thanks to a recent study using yeast cells. By exposing the cells to proteins from the virus, a team at the University of Maryland has found that seven of these proteins are harmful.
The work was led by Dr Richard Zhao, who has pioneered the use of a particular type of yeast known as 'fission yeast' for studying viruses such as Zika and HIV. “I have this unique way of dissecting the genome [of viruses],” says Zhao. "These results give us crucial insight into how Zika affects cells.”
In February 2016, the World Health Organisation (WHO) declared the Zika outbreak a Public Health Emergency of International Concern, linking the virus to incidences of a birth defect called microcephaly – literally "small head" – in Brazil.
So far, 69 countries, mostly in the Americas, have reported transmission of Zika by mosquitoes. It is now established that the virus also spreads through sexual contact. In November 2016, the WHO downgraded the virus from a global public health emergency to a serious threat that still requires further long-term research.
This new work adds to a growing body of evidence on how the Zika virus causes harm. The seven proteins identified in the study either inhibited the yeast cells' growth, damaged them or killed them. Dr Zhao is now beginning further work looking at how the virus interacts with rat and human cells.
Many questions about the virus remain, including the true size of the outbreak in Brazil (the virus usually causes no symptoms in adults, and microcephaly in babies may be caused by other factors), and why some Zika-infected women do not give birth to babies with microcephaly. It's hoped that answering these questions will help pave the way to an effective vaccine, with some researchers saying that we could have one as early as 2018.