An experimental anti-viral treatment for COVID-19 reduces viral load by 99.9 per cent holds high hopes for the future
In ground-breaking research, an international team of scientists has discovered an experimental anti-viral therapy that directly attacks the COVID-19 virus and prevents it from reproducing itself.
The therapy, which has been shown to work effectively in laboratory mice, uses a gene-silencing RNA technology called siRNA that attacks the COVID-19 genome directly, shutting down its ability to replicate.
Developed by an international team of scientists from Griffith University in Queensland, Australia, and City of Hope, a cancer and other diseases research and treatment centre in the United States, the treatment also works to deliver lipid nanoparticles to the lungs, where the virus has its most devastating and life-threatening effects.
Professor Nigel McMillan, from Griffith University, says the treatment sets out on a “seek and destroy mission” during which it genetically targets the potentially deadly virus.
“Treatment with virus-specific siRNA reduces viral load by 99.9%. These stealth nanoparticles can be delivered to a wide range of lung cells and silence viral genes,’’ says Professor McMillan, the co-lead researcher on the project.
“Treatment with the therapy in SARS-Cov-2 infected mice improved survival and loss of disease. Remarkably, in treated survivors, no virus could be detected in the lungs.’’
Professor McMillan says although the therapy is “not a cure”, it could reduce the amount of virus in the lungs by 99.9 per cent, “so it is almost as good as a cure”.
Professor McMillan says traditional antivirals like zanamivir and remdesivir reduced symptoms and helped people recover earlier.
“This therapy actually stops the virus replicating, so the body can repair itself and the recovery will be much quicker,” he says. “It is really for those people who are suffering for example in ICU, where vaccines are too late.” “Where this therapy actually stops the virus replicating, so the body can repair itself and the recovery will be much quicker,” he said.
“We basically should be able to eliminate people dying from this disease — if treated soon enough.
“It allows us to treat those people who are suffering from the virus who are extremely sick, or those who may perhaps be in danger of being exposed to the virus, such as those in hotel quarantine. They’d be assured they won’t suffer from the disease itself.
“This is really one of the first cabs off the rank in terms of a direct therapeutic, so we are really excited.
It is an injection that would be delivered daily into someone in ICU for four or five days, or as a single injection for someone just exposed.”
The treatment is designed to work on all beta-corona viruses such as the original SARS virus (SARS-CoV-1) as well as SARS-CoV-2 and any new variants that may arise in the future, says Professor Kevin Morris, co-lead researcher from both City of Hope and Griffith University. “It targets ultra-conserved regions in the virus’ genome,” he says.
The results suggest that siRNA-nanoparticle formulations can be developed as a therapy to treat human COVID-19 patients, as well as used for future coronavirus infections by targeting the virus’ genome directly.
Most importantly, the nanoparticles are economically practical and can be produced in abundant numbers. “These nanoparticles are scalable and relatively cost-effective to produce in bulk,” Professor Morris says.
“We have also shown that these nanoparticles are stable at 4°C for 12 months and at room temperature for more than one month, meaning this agent could be used in low-resource settings to treat infected patients,” Says Prof. McMillan.
“This is the first time we have been able to package this up as a particle, send it through the blood stream to attack the virus.
“It travels to the lungs and it will actually enter all the lung cells, but only in the lung cells with the virus will it destroy — normal cells are completely unharmed by this treatment.”
An approved version of the treatment could be available as early as 2023, depending on the next phase of clinical trials.