The Oxford University team in charge of developing the coronavirus vaccine said a decline in the infection rate will make it increasingly difficult to prove whether it’s been successful The Oxford University team in charge of developing a coronavirus vaccine said a decline in the infection rate will make it increasingly difficult to prove whether it’s been successful, the Telegraph reported. “It’s a race against the virus disappearing, and against time," Professor Adrian Hill, director of the university’s Jenner Institute, told the newspaper. “We said earlier in the year that there was an 80% chance of developing an effective vaccine by September.