Human testing has already begun on a coronavirus vaccine that could become widely available as early as September.

That’s according to Oxford University scientists, who say they got a head start on the rest of the world in developing a vaccine because they were able to use technology from previously-developed vaccines to formulate one that’s effective against the coronavirus. “Personally, I have a high degree of confidence about this vaccine because it’s technology that I’ve used before,” says Oxford Professor Sarah Gilbert.

To develop the new vaccine, scientists injected the coronavirus’ genetic material into a neutralized common cold virus, Gilbert says. The modified virus mimics COVID-19, prompting the immune system to develop antibodies to fight it off. The antibodies then remain in the system in case the Real McCoy comes along, Gilbert says.