Hong Kong: Scientists in Hong Kong claim to have made a potentially innovative discovery in the fight against infectious diseases – a chemical that could slow the spread of deadly viral diseases.
A team at the University of Hong Kong described the new chemical as "highly potent in disrupting the life cycle of several viruses" in a study published this month in the journal Nature Communications.
Scientists told AFP on Monday that it could one day be used as a broad-spectrum antiviral for a host of infectious diseases – and even for viruses that have not yet emerged – to undergo clinical trials.
The spread in recent decades of deadly bird flu strains, the Middle Eastern Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS) have emphasized the need for new drugs that can work faster than vaccines.
Broad-spectrum antivirals are seen as the holy grail because they can be used against multiple pathogens.
In contrast, vaccines generally only protect against a strain and, when they are produced, the virus may have mutated.
The HKU team tested its chemical "AM580" in mice in a two-year study and found that it has stopped replication of a number of flu strains – including H1N1, H5N1 and H7N9 – as well as the viruses that cause SARS and MERS.
It also halted the replication of the Zika virus transmitted by mosquitoes and Enterovirus 71, which causes hand and foot-and-mouth disease.
"This is what we call a broad-spectrum antiviral drug, which means it can kill several viruses," said Yuen Kwok-yung, a microbiologist who led the team to AFP.
"This is very important in the early control of an epidemic."
The study is part of a growing body of virologist research to find drugs that avoid directly attacking a virus – something that could lead to resistance. Instead, they look for compounds that disrupt the way viruses use the essential fatty acids, known as lipids, in the cells of a host to replicate.
"This study is science in progress – an initial step in a new and exciting direction," said Benjamin Neuman, a Texas virus expert at A & M University-Texarkana who published his own studies on hungry lipid viruses.
"Viruses are totally dependent on supplies stolen from their hosts, and several recent studies have shown that treatments that interrupt the constant flow of lipids into an infected cell are highly effective in blocking a wide range of viruses," he told AFP.
The next step is to test the drug on a wider variety of animals, including pigs and primates, before taking clinical trials, a process Yuen said could take up to eight years.
The HKU staff applied for a patent in the United States.
A derivative of AM580 is already being used in Japan to treat cancer, boosting hopes that it will show low toxicity to humans.
But Neuman warns that there are disadvantages.
Like many chemotherapy methods used to fight cancer, antivirals like the AM580 harm a person's cells to deprive a virus. While cells can heal, much research still needs to be done on how and when to use these techniques.
"Unless treatment is directed very carefully, the potential for side effects would be very disturbing," he said.
Densely populated, Hong Kong has firsthand experience of deadly viral outbreaks.
In 2003, nearly 300 people died of SARS and the densely populated apartment blocks of the city are considered extremely vulnerable to future outbreaks.