The drug firm, which has been working with Oxford University to rollout a vaccine at cost price, confirmed it will start working on a booster jab in the spring and expects mass production to begin in six to nine months time.
The AstraZeneca/Oxford vaccine is one of two jabs currently being used in the UK, of which 100 million doses have been secured, but there are concerns it may be less effective at preventing mild illness caused by the South African variant of the virus.
A study showed it provides less protection against mild illness caused by the strain, but is still effective in blocking serious disease and death.
Boris Johnson has confirmed booster jabs will be needed in the autumn to tackle the threat of new variants either home-grown or imported from abroad.
With at least 170 cases of the South African strain already in the UK, at least 24 cases of the Brazilian variant and 72 cases of new home-grown variants with the same mutation, news of a forthcoming booster jab will be welcomed in government.
Speaking at Prime Minister's Questions, the PM said people must "get used to the idea of vaccinating, then re-vaccinating in the autumn as we come to face these new variants".
He added that the government had secured 50 million doses of a vaccine developed by CureVac, "because we believe that may help us to develop vaccines that can respond at scale to new variants of the virus".
Vaccines minister Nadhim Zahawi has urged the public to keep faith with the Oxford jab as scientists working on the vaccine raised the prospect of having a booster dose available by the autumn.
Writing in the Telegraph on Monday, he said: “While it is right and necessary to prepare for the deployment of an updated vaccine, we can take confidence from the current roll out and the protection it will provide all of us against this terrible disease.
“We need to be aware that even where a vaccine has reduced efficacy in preventing infection there may still be good efficacy against severe disease, hospitalisation, and death. This is vitally important for protecting the healthcare system.”
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AstraZeneca Chief Executive Pascal Soriot said the UK should start seeing a decline in hospital admissions from the disease "very soon" thanks to the Government's rapid vaccination programme, with hopes for it to start having a marked impact from March.
AstraZeneca, which had been locked in a row with the EU over vaccine supply, also said said it is set to deliver 100 million doses of its current vaccine globally in February, doubling to 200 million a month by April.
Mr Soriot said: "100 million doses in February means 100 million vaccinations, which means hundreds of thousands of severe infections avoided and it also means thousands of deaths that are avoided."
"We're going to save thousands of lives and that's why we come to work every day as individuals," he added.
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