A review of available safety data in more than 17 million people who have been vaccinated across the UK and EU has shown no evidence of an increased risk, the pharmaceutical giant said.
People across the UK are still being urged to get their vaccine.
The number of cases of blood clots reported is lower than the hundreds of cases that would be expected among the general population, AstraZeneca’s chief medical officer Ann Taylor said.
The statement came after Irish Minister for Health Stephen Donnelly said on Sunday that use of the Oxford/AstraZeneca jab was being temporarily suspended as a “precautionary step”.
The decision followed reports of serious clotting in adults in Norway which left four people in hospital.
Several other European countries have temporarily suspended use of the Oxford/AstraZeneca jabs.
The UK’s medicines regulator said available evidence does not suggest the vaccine is the cause of the blood clots.
Dr Phil Bryan, vaccines safety lead at the Medicines and Healthcare products Regulatory Agency, said: “We are aware of the action in Ireland.
“We are closely reviewing reports but given the large number of doses administered, and the frequency at which blood clots can occur naturally, the evidence available does not suggest the vaccine is the cause.
“People should still go and get their Covid-19 vaccine when asked to do so.”
AstraZeneca said its review had found no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia, in any defined age group, gender, batch or in any particular country.
Dr Taylor said: “Around 17 million people in the EU and UK have now received our vaccine, and the number of cases of blood clots reported in this group is lower than the hundreds of cases that would be expected among the general population.
“The nature of the pandemic has led to increased attention in individual cases and we are going beyond the standard practices for safety monitoring of licensed medicines in reporting vaccine events, to ensure public safety.”
Mr Donnelly said: “The decision to temporarily suspend use of the AstraZeneca Covid-19 vaccine was based on new information from Norway that emerged late last night.
“This is a precautionary step.”
The latest developments came as charities in the UK wrote an open letter to encourage people with underlying health conditions to come forward for a vaccine.
Cancer Research UK, Mencap and the Terrence Higgins Trust are among 18 signatories to the letter aimed at people in vaccine cohort six.
The group includes carers as well as people with a range of underlying health conditions that put them at greater risk from coronavirus.
They include chronic respiratory, heart, kidney and liver disease and neurological conditions, immunosuppression, asplenia, diabetes, morbid obesity and severe mental illness.
People with sickle cell disease, lupus and those on a GP learning disability register, as well as people who have vascular disease or have had a stroke are also included in group six.
Meanwhile, the NHS is to text millions of vulnerable people with underlying health conditions asking them to take the vaccine.
People with conditions such as diabetes and certain forms of cancer will receive a link to reserve an appointment for a jab at a vaccination centre or pharmacy across England.
The UK’s national statistician said he has “no doubt” that there will be a further wave of Covid-19 infections in the autumn.
Professor Sir Ian Diamond, head of the Office for National Statistics (ONS), also said there is a lot of regional variation in terms of how many people have antibodies.
Sir Ian said people need to understand how the data is moving forward and look at the impact of the “wonderful” vaccine rollout.
“But having said that, we need also to recognise that this is a virus that isn’t going to go away,” he told The Andrew Marr Show on BBC One.
“And I have no doubt that in the autumn there will be a further wave of infections.”
His comments came after England’s chief medical officer Professor Chris Whitty said during the week that there were still risks to reopening society and the UK will experience another surge of cases at some point, potentially in late summer or through the autumn and winter.