Two coronavirus studies in monkeys published on Wednesday offer encouraging evidence that surviving the virus could result in immunity from reinfection, according to US researchers.
Although scientists assumed that antibodies produced in response to the virus were protective, there had been slim scientifically rigorous evidence to substantiate the idea, Reuters reports.
In a recent study, researchers infected nine monkeys with the virus. Once the monkeys recovered, scientists exposed them to the virus again but the animals did not get sick.
The findings suggest that the animals "do develop natural immunity that protects against re-exposure," said Dr. Dan Barouch, a researcher at the Center for Virology and Vaccine Research at Harvard's Beth Israel Deaconness Medical Center in Boston, whose studies were published in the journal Science.
"It’s very good news," Barouch said.
Other research teams have released papers which had not been peer-reviewed, suggesting that a vaccine would be effective in animals.
The second study featured Barouch and colleagues testing 25 monkeys with six different prototype vaccines to see if the antibodies produced in response were protective.
They then exposed these 25 animals and 10 control animals to SARS-CoV-2, the official name of Covid-19.
All of the control animals show substantial degrees of virus in their noses and lungs, while in the vaccinated animals, "we saw a substantial degree of protection," Barouch said. Eight of 25 vaccinated animals were protected.
These studies have been peer reviewed but do not yet prove that humans develop immunity or indicate how long it may last, though the findings are reassuring.
"These data will be seen as a welcome scientific advance," Barouch said.