Fears that the AstraZeneca vaccine could cause blood clotting continue to grow after yet another country announces it has suspended the vaccine’s roll out.

The Netherlands is the seventh country to halt the deployment of the AstraZeneca vaccine entirely, cancelling thousands of pre-booked vaccination appointments.

The Dutch government has said this move is a precautionary measure which will give them time to thoroughly investigate the matter.

How have AstraZeneca responded to blood clot claims?

Following a review of the safety of the vaccine, AstraZeneca has announced that there is “no evidence” that the vaccine increases the risk of pulmonary embolism, deep vein thrombosis or thrombocytopenia, in any defined age group, gender, batch or in any particular country.

Ann Taylor, Chief Medical Officer at AstraZeneca, 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.”

The World Health Organisation (WHO) and the European Medicines Agency (EMA) have backed this statement, confirming that there is no indication of a link between the vaccine and blood clotting.

A spokesperson from WHO, Margaret Harrison, described the vaccine as “excellent” and said there is no reason not to use it. She said: “It's very important to understand that we should continue using the AstraZeneca vaccine.

“Any safety signal must be investigated. It is very important we are hearing safety signals, because if we were not hearing about safety signals, that would suggest there is not enough review and vigilance.”

What does the evidence say about the Oxford/AstraZeneca vaccine?

According to the EMA’s database of side effects, there were 30 reported cases of blood clotting out of five million people in the European Economic Area.

From this report, scientists have concluded that there is no causal relationship between the vaccine and blood clotting. However, there have been some serious cases and deaths, which is why some countries have decided to take cautionary measures.

In Austria, a 49-year-old woman died as a result of severe coagulation disorders, while a 35-year-old woman developed a pulmonary embolism and is recovering. A 57-year-old Bulgarian woman also died of heart failure 15 hours after receiving the AstraZeneca jab.

Despite these cases, the majority of countries who have issued a suspension on the vaccine have said there is no evidence to prove the vaccine causes blood clots.

It is also worth noting that blood clots are not uncommon and can occur naturally. They are believed to cause symptoms in around one in every thousand people in the UK every year.

Which other countries have halted the rollout of the Oxford/AstraZeneca vaccine?

Indonesia, Norway, Denmark, Bulgaria, Iceland and the Democratic Republic of Congo have all suspended vaccinations for the time-being.

Italy, Austria, Estonia, Latvia, Luxembourg and Lithuania and some regions in Spain have banned jabs from one particular batch of one million vaccines.

Thailand initially postponed the vaccine roll out, but has since reviewed the evidence and announced they will start administering the jab without delay.

Should I be worried about having the vaccine?

The Medicines and Healthcare products Regulatory Agency (MHRA) has said there is no evidence that the vaccine is unsafe or causes problems and everyone should still go and get vaccinated when asked to do so.

Dr Phil Bryan, MHRA Vaccines Safety Lead said: “Vaccine safety is of paramount importance and we continually monitor the safety of vaccines to ensure that the benefits outweigh any potential risks.”

Monthly safety reports are tracking the vaccine's rollout, and are being made available on the EMA website. AstraZeneca say they are committed to sharing information without delay.

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