One of the many Covid-19 vaccines in development, a vaccine for the first time has "largely protected" monkeys from infection during an animal trial.
It is among a slew of vaccines being developed around the world as countries race to stop an outbreak that has infected around 2.7 million people globally and killed more than 190,000, data from a Chinese pharmaceutical giant showed, reported Channel News Asia.
The vaccine is an old-fashioned formulation consisting of a chemically inactivated version of the virus, produced no obvious side effects in the monkeys, and human trials began on April 16, reported the Live Science.
"It injected two different doses of its vaccine into eight rhesus macaque monkeys and exposed them to the virus three weeks later, and they did not develop infections," Nasdaq-listed Sinovac Biotech said.
All the monkeys "were largely protected against SARS-CoV-2 infection", Sinovac said in its findings.
Four macaques who received a high dose of the vaccine had "no detectable" amounts of the virus in their lungs seven days after they were administered the pathogen.
Another four monkeys given low doses showed an increase in the viral load in their bodies but appeared to have controlled the virus on their own, it said.
In contrast, four monkeys who were not given the vaccine fell ill from the virus and suffered severe pneumonia.
Sinovac published its results on the online server bioRxiv on April 19, three days after it began human trials, but its findings have yet to be peer reviewed by the global scientific community.
Earlier, the experimental antiviral drug remdesivir has failed in its first randomized clinical trial to treat the Covid-19 illness, reports said Thursday, quoting draft documents that were accidentally published by the World Health Organization.
The Financial Times reported that researchers in China carried out a study on 237 patients, giving the drug to 158 and comparing their progress with a control group of 79.