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How safe is the AstraZeneca vaccine?

The UK medicines regulator has said people under 30 should be offered an alternative to the Oxford-AstraZeneca vaccine due to concerns about rare and unusual blood clotting.

As a precautionary measure, people aged 18 to 29 should be given the Pfizer or Moderna vaccine instead, said the Medicines and Healthcare products Regulatory Agency (MHRA)


The regulator said there was not yet proof that the jab had caused the clots, but that evidence of such a link was “firming up”. It stressed that the cases were extremely rare and, for most age groups, the benefits of getting vaccinated outweigh the risks.

What are the blood clot concerns?

Regulators in the UK and Europe have been investigating reports of rare blood clotting cases combined with low platelet counts in people who have been vaccinated with the Oxford-AstraZeneca jab.

Data released by the MHRA today during a news conference identified 79 cases, 19 of them fatal, of rare blood clots, out of more than 20 million doses given. Overall, there were 51 women and 28 men among the cases, with ages ranging from 18 to 79. They included cases of a specific type of clot known as cerebral venous sinus thrombosis (CVST), which stops blood from draining from the brain.

The agency suggested the risk factor for such clots is around four in a million.

What else has the MHRA said?

Dr June Raine, chief executive of the MHRA, said the benefits for older people of having the AstraZeneca vaccine far outweigh the blood clot risks, but she said it is more “finely balanced” in young people who are less likely to die from Covid.

Anyone with the following symptoms after their vaccine should seek medical help:

  • Headaches

  • Blurred vision

  • Shortness of breath

  • Chest pain

  • Leg swelling

  • Abdominal pain

  • Bruising or pinpoint spots beyond the vaccination site

What are other countries doing?

The jab has had a “mixed international reception”, reported The Times last week. Britain has been - so far - “staunchly supporting its use”, while South Africa “outright rejected” it, the newspaper continues.

On Friday, the Netherlands became the latest country to stop the vaccine for under-60s. Several EU countries suspended the vaccine last month before restarting their rollouts after the European Medicines Agency (EMA) said the benefits outweighed the risks. But a “patchwork of age restrictions” remains in place, and Canada halted the use of the jab for under-55s last week “pending further analysis”.

The EMA, which held a separate news conference at the same time as the MHRA today, said unusual blood clots with low blood platelets should now be listed as a very rare side effect, confirming a “possible link” between the two. However, it backed the vaccines’ use in all adults.

“Covid-19 is associated with a risk of hospitalisation and death,” the EMA said. “The reported combination of blood clots and low blood platelets is very rare, and the overall benefits of the vaccine in preventing Covid-19 outweigh the risks of side effects.”

The AstraZeneca blood clot risk in context

Experts say odds of adverse side effect are about the same as 'being hit in your home by crashing aeroplane'

Confidence in the UK’s Covid vaccination programme risks being undermined by news that under-30s will be offered an alternative to the Oxford-AstraZeneca jab as a result of blood clot concerns, experts have warned.

Government scientists and ministers are expected to “embark on a media blitz” to persuade the public that the vaccine is still safe following the announcement by regulators, The Times reports. And media outlets have also been putting the risk into context.

What was announced?

The Joint Committee on Vaccination and Immunisation (JCVI) issued a statement yesterday about “extremely rare” cases of blood clots combined with low platelet counts in a small number of people who had the Oxford-AstraZeneca vaccine. No such cases have been reported in recipients of the Pfizer-BioNTech or Moderna vaccines, the independent advisory body said.

The JCVI experts emphasised that the benefits of the protection that the AstraZeneca vaccine offers against Covid “far outweigh” the risks of an adverse reaction in the vast majority of people. But the committee is advising that adults under 30 without underlying health conditions should be offered an alternative vaccine “if available”.

The recommendation follows a review by the Medicines and Healthcare products Regulatory Agency (MHRA), which concluded the risk vs. benefit of the AstraZeneca jab is more “finely balanced” for younger people, who are generally less likely to die from Covid.

What are the numbers behind the decision?

The MHRA says it received 79 reports of blood clotting and low levels of platelets in UK recipients of the AstraZeneca jab up to and including 31 March, out of 20.2 million doses administered nationwide.

The affected recipients were aged between 18 and 79 years and comprised 51 women and 28 men (the drugs regulator noted that more women have received the jab than men).

All of the blood clot cases occurred after the first dose was administered and 19 were fatal.

So how great is the risk?

The MHRA estimates that the overall risk of these blood clots is approximately four people in a million, or one in 250,000, who receive the vaccine. According to the BMJ, that equates to about the same odds of “being hit in your home by a crashing aeroplane”.

Sky News points out that the US National Blood Clot Alliance estimates that one in 1,000 women who are taking birth control pills will develop a clot each year. And the chances of developing deep vein thrombosis on a plane journey of more than four hours is around one in 4,656 flights, the broadcaster reports.

Why is the advice from European regulators different?

Separate advice issued by the European Medicines Agency (EMA) yesterday does not advise limiting the AstraZeneca vaccine for any age groups, with the regulator insisting that the overall benefits outweigh the risks for all recipients.

Graphics from the University of Cambridge’s Winton Centre for Risk and Evidence Communication offer “important context” for the EMA’s slightly different position, says The Spectator’s James Forsyth.

The data shows how the benefits vs. risks balance changes for different age groups depending on the likelihood of Covid exposure. In the UK, where the chances of getting Covid is currently lower than in Europe, the potential harms narrowly outweigh the potential benefits of having the jab for under-30s.

JCVI expert Adam Finn says Britain also has “extremely detailed data” based on the high number of AstraZeneca jabs it has administered, compared with the EU.

Despite the slight disparity between the guidelines from the two sides of the Channel, however, the regulators are united in the messaging about getting inoculated against Covid.

Professor David Spiegelhalter, chair of the Winton Centre, told BBC Radio 4 this morning that young people should still get vaccinated, not only for their own benefit, but for their families, friends and neighbours too.

Meanwhile, a government spokesperson insisted the AstraZeneca vaccine is “safe, effective and has already saved thousands of lives”.

But Dr Chris Papadopoulos, principal lecturer in public health at the University of Bedfordshire, has warned that the UK advice change has dealt “a severe blow to the public’s vaccine confidence, which is already fragile”.

The government push to calm jab fears is being backed by the sister of Neil Astles, the first named Briton to die from a blood clot on the brain after having the AstraZeneca vaccine.

Dr Alison Astles, pharmacy lead at Huddersfield University, told TheTelegraph that her brother had been “extraordinarily unlucky”, but that she “trusted the process”.

“If we all have the vaccine, a few of us might have a blood clot,” she said, “but the evidence is that fewer people will die.”

Source: here

There has been a substantive amount of media coverage and adverse publicity regarding some safety aspects concerning the Oxford AstraZeneca (OxAZ) vaccine. Across the UK and Europe, there have been over 20 million doses of the OxAZ vaccine administered. There have been 79 cases of a rare clotting abnormality reported in 51 women and 28 men (18-79 years) with only 19 fatalities. Putting this into context the overall risk is 4 per 1 million population or another way to look at this, is that your chances of a plane falling out of the sky and crashing into your home is greater. There is still no proven causal link between OxAZ vaccination and the rare types of clotting found in a few individuals. A major consideration is the overall benefit of being vaccinated versus the potential side effects. Countries which have temporarily suspended the use of the OxAZ vaccine have exposed their populations to COVID-19 infection and with it, a 2.5-5% mortality (depending on age, state of the healthcare system and the presence of comorbid disease), and if people with COVID-19 infection survive, many have the disabling long COVID symptoms which include severe fatigue, breathless, brain fogging and mental illness in 1 in 3 individuals. This article highlights that the advice in the UK, based on the current information is that people aged 18-30 years should be offered either the Pfizer BioNTech or Moderna vaccines. The rational for this arbitrary age divide is explained balancing the potential benefits versus the potential harm from the vaccine in age specific groups and for low and high risk COVID-19 exposure. This is a 6 minute read. This material has been drawn together by the UK Week staff from reputable sources. - Doctor Donald Greig


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