Chinese biotech firm says COVID-19 vaccine protects monkeys
25 April, 2020
A novel coronavirus vaccine has for the very first time "largely protected" monkeys from infection during an animal trial, data from a Chinese pharmaceutical giant showed.
It is among a slew of vaccines being developed all over the world as countries race to stop an outbreak which has infected around 2.7 million persons globally and killed a lot more than 190,000.
Nasdaq-listed Sinovac Biotech said it injected two different doses of its vaccine into eight rhesus macaque monkeys and exposed them to the virus three weeks later, plus they didn't develop infections.
All the monkeys "were largely protected against SARS-CoV-2 infection", Sinovac said in its findings.
Four macaques who received a higher dose of the vaccine had "no detectable" levels of the virus within their lungs seven days after they were administered the pathogen.
Another four monkeys given low doses showed a rise in the viral load within their bodies but seemed to have manipulated the virus on their own, it said.
On the other hand, four monkeys who weren't given the vaccine fell ill from the virus and suffered severe pneumonia.
Sinovac published its results on the web server bioRxiv on Apr 19, three days after it began human trials, but its findings have yet to be peer reviewed by the global scientific community.
The vaccine, like the majority of others, uses a chemically inactivated novel coronavirus pathogen to greatly help the body build immunity against the true disease.
Tests had proven "good efficacy" and the Beijing-based company was confident about the vaccine's potential, Sinovac spokeswoman Yang Guang told AFP.
The business had given "the first serious pre-clinical data I have seen for a genuine vaccine candidate", said Florian Krammer, a virologist at the Icahn School of Medicine at Mount Sinai in New York.
Krammer recently co-authored a survey of different coronavirus vaccine projects for the journal Cell.
He said on Twitter that the vaccine's make use of inactivated viruses was "old-fashioned technology" which would make it simpler to scale up production.
MUTATION RISK
Several strains of the novel coronavirus have already been found by researchers, showing that the pathogen slowly mutates, potentially making the development of a vaccine harder.
But Sinovac said its experiment up to now had demonstrated its vaccine can "neutralise" widely different strains found among patients in China, Italy, Switzerland, Spain and Britain.
"This gives strong evidence that the virus is not mutating in a manner that would make it resistant to a #COVID19 vaccine," immunologist Mark Slifka from Oregon Health & Science University tweeted.
However, vaccines with inactive pathogens need booster shots to stay effective and it remained to be observed whether Sinovac's research would provide "long-lasting protection" from the virus, said Lucy Walker, professor of immune regulation at University College London.
Phase three testing of the vaccine will need human volunteers who were never infected with the condition as well as those with symptoms.
Sinovac's Yang said the business was looking abroad for test subjects as China now doesn't have enough reported COVID-19 cases.
Chinese authorities have approved three clinical trials for vaccines so far, but have not yet signed off on phase three trials for Sinovac's effort.
There are no approved vaccines or medications for the new disease.
The World Health Organization has said it could take 12 to 1 . 5 years to build up a vaccine.
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