Britain's Oxford University and its pharmaceutical partners, AstraZeneca, have published the preliminary results from large scale trials, and they show their vaccine is 70% effective at protecting people from the disease.

But in a sub group of volunteers who received ah half dose, followed by a folders, the effectiveness rose to 90% In the last few weeks, Pfizer and Biotech and Madonna published their results, which said that there to dose vaccines were 95% effective.

However, the Oxford vaccine, it's cheaper and easier to store than the other two vaccines, since it can be stored at fridge temperature.

Andrew Pollard is head of the Oxford Vaccine Group.

He's been telling us about the success off his vaccine.

We're really pleased with these results.

What we found is that overall in the trials across the UK in Brazil, we've managed to prevent about 70% of infections.

But importantly in people who were vaccinated with the new coronavirus vaccine, no one was hospitalized or had severe disease.

So at that sort of 70% of figure is giving us an idea about the overall protection, including the mild infections on intriguingly, in one of the groups that we had, what we gave a half dose of the first dose on, then a full dose.

We saw 90% protection on DSO.

That suggests that we've got a regimen of vaccinating but might allow a lot more doses to be used, because we only need half a dose for the first one. And yet we're seeing even higher protection.

There's also really interesting hint in the data that that regimen is also able to reduce asymptomatic infection.

And if that's the case, it might allow us to get to a point where we could halt the virus in its tracks on it can't transmit from person to person.

So I think this is very exciting news.

There's there's obviously going to be a lot more data to come on over the next month or so.

But as a first interim look at the data, I think this is incredibly positive that we have a vaccine that could be distributed using the normal immunization systems through fridges around the world on, because it's a partnership that we set up with AstraZeneca that's not for profit is going to be affordable everywhere that we can get it.

Andrew Quality can't keep the smile off his face With me is our global health correspondent, Naomi Grimly.

We've still got lots of questions about this, namely, But to start with what great news?

Yes, absolutely.

And bear in mind that the Food and Drug Administration in the U.

S.

Was getting ready.

Thio approved vaccines that had only 50% efficacy.

So to hear that there's one that has overall efficacy of 70% maybe up to 90% is another good day in this crisis.

What are the implications for the developing world given?

We've just heard it's cheaper to produce and, more importantly, you can store it in the fridge.

Indeed, that's really important, because one of the big worries with Pfizer and Madonna is that they were going to need special carrying boxes and special freezers to get it around the world.

And, of course, when you're trying to get it to hard to reach communities, particularly in hot countries, that is problematic.

The Big plus with Oxford AstraZeneca is they will be ableto piggyback on food Onda drink logistics if you like.

So already organizations like UNICEF in the W H O a.

Talking to those distribution chains and working out how they can use them.

Thio good effect.

So how quickly will it be available?

Well, that's really difficult, Thio put a finger on at the moment.

Here in the UK, we're told that the first four million doses could be available by the end of the year, but when we're talking about developing countries, it will be a much bigger logistical operation.

The good thing again, though, is that Oxford and AstraZeneca have already done deals with places like the Serum Institute in India.

Also manufacturers in places like Brazil.

So it's already being made.

And as soon as it gets approval, it can be used in terms of the difference between this vaccine and others.

Andrew there was just talking about the lower levels of asymptomatic infection in one group.

We didn't hear that about the other two vaccine.

No, that that's right Oxfords done this particular monitoring of asymptomatic cases in its huge trials on They do think it helps dampen down at the infection infectiousness of this disease and prevent infection altogether.

And that's really important because all along in this crisis, the big problem has bean.

It flies beneath the radar.

If you like, you and I could be going out for a drink and not realize that were actually infecting each other.

Okay, there's so much good news we've just discussed.

What are the uncertainty?

Still, what don't we know?

Name?

The big uncertainty with all three of the vaccines we've heard about so far is how long we get protection for in a previous vaccine for MERS, That's Middle East respiratory syndrome.

It lasted a year, so we don't know whether it will be a good is that or lesser?