Even before modification, Oxford scientists say their vaccine is highly effective in tackling the runaway variant first discovered in the United Kingdom. Real-life preliminary data shows that it kept hospitalizations down by 94%, even outperforming the Pfizer vaccine.

“We’ve seen the first widespread use of a vaccine in a setting where there’s been a new variant that’s emerged,” Oxford Vaccine Group head Andrew Pollard told CBS News. “The vaccine has an impact against that variant. That is astonishing.”

Part of the reason for that success is the 12-week gap between shots in the U.K., rather than the four-week program currently standard in the U.S., Pollard said.

“If you give that vaccine to many, many more people as the first dose, that ends hospitalization and deaths immediately, while if you give two doses close together, you’ll be selfishly giving those two doses to half the number of people, slowing down that rollout and the protection of the population,” Pollard said.