Breakthrough in developing Zika drug

In a busy lab at the Institute of Organic Chemistry and Biochemistry (IOCB) in Prague's Dejvice district, home to many of the city's best technical universities and research institutions, a rack of condensers whirs away on a shelf. Around them, scientists in white coats peer into microscopes as they create chemical compounds to fight a virus for which there is no vaccine and no specific treatment.

"There is a family of viruses called the flaviviridae family, and Zika is one of those viruses," Dr Radim Nencka, junior group leader in medicinal chemistry at the IOCB told DW. "We've been recently focused mostly on this family of viruses; in particular we've been working on tick-borne encephalitis and also on the West Nile Virus, which is already connected or very similar to the Zika virus," Dr Nencka explained.

Attacking building blocks of the virus

"So we started to work on these two viruses, and we were focused on treatment of these viruses. And once the Zika outbreak occurred, we decided to look at Zika as well," he said. "So it was a logical step forward for us."

Dr Nencka and his team believe they may have found Zika's Achilles Heel, a weakness they can exploit to stop it replicating. "Every virus needs some specific building blocks for its life cycle, for its replication, which are called nucleosides (and) nucleotides," Dr Nencka explained.

"We modify these building blocks so they can stop the replication, they can stop the process. And we must be very specific, because also our cells are using nucleosides and nucleotides for the processes that are necessary for our own cells. So these compounds must specifically inhibit only the enzymes, the tools of the virus," he added.

Promising results

Dr Nencka sends his compounds for testing to scientist Daniel Ruzek, who heads groups at both the Biological Centre of the Czech Academy of Sciences based in Ceske Budejovice and the Brno-based Institute of Veterinary Medicine. He then puts the compounds to the test on infected organisms. Though Daniel Ruzek, too, stressed this is in its early days.

"Actually we are just at the beginning. We know which compounds are active against the virus. We have some promising results, and we know where the Achilles' heel is of the virus that we can target by the compounds. But that's still not the final drug," Ruzek told DW.

"Some people have asked me how the compound will be applied: if this will be a pill or in the form of an injection. I can't answer anything like that because we are still at the beginning," he added. "We still need to modify the active compounds into so-called pro-drug forms. These pro-drugs should have improved pharmacological properties, should be better targeted to the organs in the body (and) should be slowly eliminated from the organism." So there's still a long way.

Troubled Olympics

Certainly a treatment will not be ready in time for the Rio Olympics – with so much concern over Zika, especially for pregnant women, many of whom in Brazil have given birth to infants with the distressing deformation in infants known as microcephaly.

Within five or 10 years, however, scientists might be ready to produce medication that could stop Zika replicating and passing on from mother to child. And a vaccine? That could be even further in the future.