Scientists are optimistic that they may have moved a step closer to finding a vaccine against coronavirus, after a successful lab test on mice.
Newly published research shows scientists used an engineered virus to protect lab mice against a lethal dose of MERS, a virus which is very similar to COVID-19.
They now have hopes that a similar method could work in the fight against Sars-CoV-2, the virus that causes the disease COVID-19.
In order to protect the mice from MERS, scientists infected them with another virus - called parainfluenza virus 5, or PIV5 - which affects some animals but is harmless to humans.
The PIV5 was engineered by scientists so that it would produce glycoprotein, known to be involved in MERS infections.
"We know people have been exposed to PIV5, but it seems to be an innocuous virus in humans," said Dr Paul McCray, a coronavirus expert from the University of Iowa who co-led the study.
The mice were given a single dose of the vaccine before being infected with MERS four weeks later.
Researchers said that the engineered virus triggered immune responses against the disease in mice. Those given the vaccine survived after being infected with a strain of MERS while another group of mice that weren't given the vaccine did not survive.
Dr McCray said finding a vaccine that protects against COVID-19 is a race against time.
"One hundred percent of the population is not going to be exposed to the virus the first time around, which means there will be more people to infect when it comes again," he said. "We don't know yet if people get lasting immunity from the SARS-CoV-2 infection, so it's important to think about ways to protect the population."
The research was published in mBio, a journal of the American Society of Microbiology.