Risk of deadly blood clots increases if you reject vaccine and catch Covid, study warns

YOUR risk of a deadly blood clot is higher if you don’t get the vaccine and catch the coronavirus, a study has warned.

Vaccines have been linked with cases of blood clotting in a tiny number of people since March, but are still deemed safe and effective.

Health chiefs have urged people to keep coming forward for their shots regardless of the tiny risk.

And a new study further confirms people are better off accepting their jab invite than not.

It looked at six million people in Catalonia, Spain, of which some 1.3 million had been vaccinated with either one or two doses of AstraZeneca of Pfizer.

A further 222,710 people who had previously had Covid were included in the study.

Researchers in Spain, funded by the European Medicines Agency (EMA), were looking for cases of blood clotting disorders.

Scientists said the Pfizer and AstraZeneca vaccines had “similar safety profiles” in this study, meaning one was no worse than the other.

But they cautioned less people in the study had been given AstraZeneca, so those figures are less reliable. 

“Regardless of the vaccine used, the increase in rates of thrombosis among persons with Covid-19 is far higher than those seen among persons vaccinated,” the experts said.

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Although Covid is primarily a respiratory disease, it’s impact on the circulatory system and blood paves the way for blood clots.

It’s theorised the virus irritates the cells that line blood vessels, causing them to release proteins that trigger clotting.

Covid may also drive an overactive immune response, leading to inflammation that can cause blood clotting.

Blood clots can lead to deadly strokes, heart attacks or block the lungs. Many critically ill Covid patients sadly would have died of this complication.

Cases of venous thromboembolism – when a blood clot forms in a vein, most commonly in the deep veins of the legs or pelvis – were 1.3-fold and 1.15-fold higher after the first dose of a Pfizer or AstraZeneca jab, respectively.

After Covid diagnosis, it was eight times higher.

The risk of low blood platelets was 1.35-fold higher after the first Pfizer jab, but 3.5-fold higher after Covid.

TINY RISK

There were no cases higher than expected for thrombosis with thrombocytopenia syndrome (TTS) after the Pfizer jab, but fewer than five after AstraZeneca.

TTS is a combination of blood clotting with low blood platelets and is what medicine regulators have been watching closely for in people who have had a Covid jab, particularly from AstraZeneca.

In the UK, there have been 411 cases reported to the Medicine and Healthcare products Regulatory Agency in people who have had the AstraZeneca jab, as of July 14. Of these, 71 ended in death (17 per cent).

But put into perspective, it’s a tiny proportion of the 47.5 million doses administered.

There have been 15 cases after 32.1 million doses of the Pfizer jab and none in Moderna.

The paper was published as a and has not been reviewed by other scientists.

But commenting today, Prof Kevin McConway an emeritus professor of applied statistics, The Open University, said: “It’s important to understand that this report doesn’t just concentrate on the specific blood clotting issues that led to the Oxford/AstraZeneca vaccine not being recommended for use in younger people in several countries.  

“The new study does report data about this syndrome, and the researchers did not find evidence of increased risk of TTS with people who had had the Pfizer/BioNTech vaccine. 

“But, because this condition is so rare, it did not arise often enough in their sample of people who had had the AZ vaccine to allow a conclusion.  

“Therefore, on TTS, the findings of this new study aren’t very conclusive because the condition is very rare, but, taking that into account, they do not go against previous findings on TTS. 

“Most of the results in the new study are about other types of blood clotting event.”

In total some 71 per cent of adults in the UK have had one dose of their coronavirus vaccine, while 88.3 per cent have had two.

New data reveals Covid vaccines have prevented an estimated 22 million infections and 60,000 deaths in England.

Jabs are also estimated to have directly averted more than 52,600 hospital admissions, new figures from Public Health England (PHE) suggest.

The latest modelling on the rollout shows the “remarkable impact” jabs have had on saving lives and reducing the spread of coronavirus, said Dr Jamie Lopez Bernal, consultant epidemiologist at PHE.

He said: “It remains vital that everyone gets two doses of the vaccine, to protect you and those around you from Covid-19. You must book your second jab when invited, to gain maximum protection.”