Drug to treat Zika infection comes closer

Scientists have discovered a compound that prevents the Zika virus from spreading, a step towards finding a drug to treat the infection, which has become a global epidemic.
"We identified a small molecule that inhibits the Zika virus protease, and show that it blocks viral propagation in human cells and in mice," said Alexey Terskikh, associate professor at Sanford Burnham Prebys Medical Discovery Institute (SBP) in the US.
"The fact that the compound seems to work in vivo is really promising, so we plan to use it as a starting point to make an even more potent and effective drug," said Terskikh.

The team took advantage of a library of compounds that SBP professor Alex Strongin's lab had previously shown to inhibit the same component of the related West Nile virus.
They also tested structurally similar molecules to determine whether any also blocked the protease.
The screening process identified three promising compounds, which were then tested for their ability to prevent Zika infection of human brain cells.

The best one of these also reduced the amount of virus circulating in the blood of Zika-infected mice.
"The inhibitor's efficacy in animals is the key to the study's significance. This, and the fact that the compound is likely to be safe make it especially promising," Terskikh said.

"The compound blocks a part of the protease that is unique to viruses, so it does not inhibit similar human proteases. It is also much more potent than previously identified inhibitors of the Zika protease," said Terskikh.
The Zika virus has been declared a public health emergency of international concern by the World Health Organisation (WHO), a rare designation indicating that a coordinated global response is needed.
Zika has been linked to an increase in cases of microcephaly, a birth abnormality in which the head and brain are unusually small, and Guillain-Barre syndrome, a rapidly developing neurological condition that causes weakness of the arms and legs and can progress to life-threatening respiratory failure.

"Microcephaly is likely just the tip of the iceberg in terms of the potential adverse effects of maternal Zika infection," said Terskikh.
This future drug is just one part of the fight against Zika. An experimental vaccine is set to move into phase 2 clinical trials in June.
The finding was published in the journal Antiviral Research.