Results of a human test of a coronavirus The vaccine may be available in mid-June, an expert said.
Sir John Bell, professor of medicine regius at Oxford University, said "several hundred" people were vaccinated and the challenge now is to be able to manufacture on a scale once approved by regulators.
In late April, a team of researchers in Oxford began testing a Covid-19 vaccine on human volunteers.
About 1,110 are expected to participate in the study, half receiving the candidate vaccine and the other half (the control group) receiving wide availability meningitis vaccine.
Professor Bell told BBC Radio 4's Today program: "We also want to make sure that the rest of the world is ready to make this vaccine on a scale, so as to reach populations in developing countries, for example, where the need It's very big. .
"We really need a partner to do this and that partner has a great job in the UK, because our vaccine manufacturing capacity in the UK is not where it needs to be and therefore we will work together with AstraZeneca to improve that. Considerably. . "
He rejected the idea of challenge therapy – which would deliberately infect healthy volunteers with coronavirus – and said there should be results in testing the vaccine using normal exposure to the virus, if you keep your head down.
Professor Bell said, "Well, we have over 1,000 people who want to start the phase 1/2 project.
"And so far so good, and now we are starting to wait for a defense signal to see if the people who were vaccinated are not getting the disease, so that's the next step."
He added that with the disease on the decline, there is a risk that there are not enough active diseases to capture people.
"We are doing these calculations because we now have very good data on the number of existing diseases," said Bell.
He also explained that the researchers discussed deliberately exposing people to the virus, but the practicalities are complicated, as there is still no treatment to rescue people if they become ill.
He added that in order to check its effectiveness, you would need to give the virus to those most at risk, and the risk of them dying would be very high if it didn't work.