AstraZeneca PLC (LON:AZN) defended its Coronavirus (COVID-19) vaccine after its suspension in the Netherlands and the Republic of Ireland.
The Dutch government said the decision was taken as a precaution and the halt will last until March 29.
READ: AstraZeneca vaccine suspended in Denmark over side effect concerns
Denmark, Norway, Bulgaria, Iceland, Thailand, Austria, Estonia, Latvia, Lithuania and Luxembourg have put on hold the rollout over concerns about cases of blood clots reported in Norway.
However, the FTSE 100 pharma giant said that a review of all available safety data of the 17mln people who have received the jab in the EU and UK has shown no evidence of an increased risk of pulmonary embolism, deep vein thrombosis (DVT) or thrombocytopenia.
So far across the EU and UK, there have been 15 events of DVT and 22 events of pulmonary embolism reported among those given the vaccine.
But the Anglo-Swedish firm said the number is “much lower than would be expected to occur naturally in a general population of this size and is similar across other licensed COVID-19 vaccines”.
"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," echoed the UK's health regulator.
"People should still go and get their COVID-19 vaccine when asked to do so," the Medicines and Healthcare products Regulatory Agency said on Sunday.
Professor Andrew Pollard, who worked on the jab at Oxford University, said that 3,000 cases of blood clots occur in the UK every month.
"So, when you then put a vaccination campaign on top of that, clearly those blood clots still happen and you've got to then try and separate out whether, when they occur, they are at all related to the vaccine or not," he told the BBC.
"I think at this moment we've got the most data from the UK, which looks very reassuring, but of course it's absolutely right that there's careful monitoring of safety and this gets looked into."
The European Medicines Agency (EMA) said last week there was no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine, but it was investigating the case.
The view was echoed by the Canadian health authority and Australian Prime Minister Scott Morrison.
The World Health Organisation said last week the jab was not linked to the blood clots though it was investigating the matter.
The EU is set to receive about 76mln of the planned 180mln of the Oxford jab in the second quarter this year.
"The risk of blood clots associated with AZD1222 [the vaccine] appears to be lower than the level observed in the overall population. This is particularly relevant given most people vaccinated so far are in high risk groups for blood clots (e.g. older age) and may have had COVID-19 in the past (also a risk factor for blood clots)," analysts at Shore Capital commented.
"Without knowing the individual patient histories, it is difficult to draw firm conclusions. For instance, reports of “unusual symptoms” in some patients, would require knowledge of the individual patients and their comorbidities to try and understand the potential role of the vaccine in causing the blood clots. For instance, if many patients have risk factors associated with blood clots (likely), it would be difficult to disentangle the individual risk contributed from the vaccine given the small sample size involved."
"There is no firm evidence currently that AZD1222 is causing the blood clots that have been reported and further data is required to understand the data observed," the broker concluded.
Shares in AstraZeneca were flat at 6,950p early on Monday, having shed 6% in the year to date and risen only 12% since March 2020 levels.
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