The AstraZeneca Scare May Be Overdone, But Rare Side Effects May Still Occur

Eighteen countries have now suspended use of the Oxford-AstraZeneca vaccine pending a review by the European Medicines Agency (EMA) into concerns about it causing serious blood clots. They are: Sweden, France, Italy, Spain, Germany, Iceland, Portugal, Ireland, Bulgaria, Denmark, Slovenia, Netherlands, Norway, Luxembourg, Cyprus, Latvia, Indonesia and Venezuela.

Many scientists and commentators have criticised the regulators and governments taking these decisions as misapplying the precautionary principle – in a number of cases, as Toby notes, speaking without a hint of self-awareness as those same commentators have been cheerleaders of the lockdowns for the last 12 months, typically justified through an abuse of the precautionary principle on scant data.

The head of Italy’s medicines regulator, Nicola Magrini, today claimed the bans across Europe were part of a politically driven snowball effect with countries within the EU coming under pressure to follow suit. Given the hard time European countries have given the Oxford jab in recent weeks (definitely not because it’s British, of course) – swinging, as Ross Clark remarks, “from accusing the company – and Britain – of hoarding the vaccine and failing to supply it to EU countries, to claiming that it is ineffective, back to accusing us of hoarding it again” – it is easy to buy this argument and suspect the actions are not simply all about safety. If that is so, you have to wonder what these governments think they’re doing, playing politics with vaccines, and whether their electorates will thank them for depriving them of long-awaited inoculations for the sake of scoring a few points against renegade Blighty and awkward AstraZeneca.

Is there anything to the concerns? Commentators today have been quick to point out that COVID-19 is “100,000 times more dangerous, compared to the tiny possibility of an issue with clotting”. There is also the inconsistency (raising questions of politics again) of targeting the AstraZeneca vaccine when, according to data from the MHRA, more people have reported blood clots after having the Pfizer vaccine than the Oxford one – up to February 28th there were 38 reports from 11.5 million doses of Pfizer, compared to 30 from 9.7m of AstraZeneca.

On the other hand, blood disorders as a whole have been reported at more than twice the rate in relation to the AstraZeneca shot compared with Pfizer, while a letter in the BMJ yesterday argued that if you look at reports of deep vein thrombosis and vascular (blood vessel) disorders then the Oxford vaccine comes out much worse.

The latest ADR reports published by the MHRA state that 11.5m doses of the Pfizer vaccine and 9.7m doses of the Oxford Astra Zeneca vaccine have been given in the UK between December 9th 2020 and February 28th 2021.

Fourteen cases of deep vein thrombosis have been reported with the Oxford AstraZeneca vaccine and only eight with the Pfizer brand.

Overall in the category of “vascular disorders” the Oxford vaccine has 1,635 reports and three fatalities with the Pfizer brand having only 1,119 reports and one fatality.

Evidently one is more likely to suffer a disorder of this kind with the Oxford vaccine than the Pfizer one.

A chorus of defence for the AstraZeneca jab rang out today, as the Mail reports.

European Medicines Agency (EMA) bosses said they were “firmly convinced” that injections with the AstraZeneca shot should continue. Safety experts said a “very small number of people” have come down with blood disorders but there is “no indication” the jab was to blame.

It joined the World Health Organization and the UK Government in offering a full-throated defence of the vaccine amid fury at European heavyweights for suspending the jabs.

Prime Minister Boris Johnson also waded into the row today, insisting the AstraZeneca vaccine is safe and saying he would be “very happy” if he is given it when he goes to his first Covid vaccination appointment this week. …

An Oxford University spokesperson echoed the balance of risk comment and said: “Both the MHRA and EMA have said that the vaccine’s benefits continue to outweigh any potential risks, and the vaccine can continue to be administered while investigation of cases of thromboembolic events is ongoing, a stance also supported by the WHO.”

Germany’s medicine regulator the Paul Ehrlich Institute published a detailed FAQ to explain its controversial actions and recommendations.

A specific form of severe cerebral venous thrombosis associated with platelet deficiency (thrombocytopenia) and bleeding has been identified in seven cases (as of March 15th 2021) in temporal association with vaccination with COVID-19 Vaccine AstraZeneca.

(1) It is a very serious disease that is also difficult to treat. Of the seven affected individuals, three individuals had died.

(2) The affected individuals had ages ranging from about 20 to 50 years.

(3) Six of the affected persons had a particular form of cerebral venous thrombosis, called sinus vein thrombosis. All six individuals were younger to middle-aged women (see above). Another case with cerebral haemorrhage in platelet deficiency and thrombosis was medically very comparable. All cases occurred between four and 16 days after vaccination with COVID-19 Vaccine AstraZeneca. This presented as a comparable pattern.

(4) The number of these cases after vaccination with COVID-19 AstraZeneca is statistically significantly higher than the number of cerebral venous thromboses that normally occur in the unvaccinated population. For this purpose, an observed-versus-expected analysis was performed, comparing the number of cases expected without vaccination in a 14-day time window with the number of cases reported after approximately 1.6 million AstraZeneca vaccinations in Germany. About one case would have been expected, and seven cases had been reported.

(5) The younger to middle-aged population affected by the severe cerebral venous thrombosis with platelet deficiency is not the population at high risk for a severe or even fatal COVID-19 course.

(6) In addition to the experts from the Paul Ehrlich Institute, other experts in thrombosis, haematology, and an adenovirus specialist were consulted with the details of the reported cases. All experts agreed unanimously that a pattern could be discerned here and that a connection between the reported above-mentioned diseases and the vaccination with COVID-19 Vaccine AstraZeneca was not implausible. After an overall review and consideration of the above facts, the Paul Ehrlich Institute recommended that vaccination with the COVID-19 Vaccine AstraZeneca be suspended in Germany as a precautionary measure in order to further analyse the cases. The German Federal Ministry of Health (BMG) has followed this recommendation. The Pharmacovigilance Risk Assessment Committee (PRAC) at the European Medicines Agency (EMA) will review during the week of March 15th 2021, whether and how the new findings affect the benefit-risk profile of COVID-19 AstraZeneca and the EU authorisation of the vaccine

Meanwhile Sweden’s Anders Tegnell has indicated his country has suspended the vaccine over concerns about a different, unspecified side effect.

However, the EMA is clear that it remains “firmly convinced” of the benefits of the vaccine. Its safety committee will meet and reach a conclusion on Thursday, reports France24.

“We are still firmly convinced that the benefits of the AstraZeneca vaccine in preventing COVID-19 with its associated risk of hospitalisation and death outweigh the risk of these side effects,” EMA chief Emer Cooke told an online press conference.

“At present there is no indication that vaccination has caused these conditions. They have not come up in the clinical trials and they are not listed as known or expected side effects,” Cooke added.

Clinical trials had shown “very small numbers of blood clot developments”, she added.

The Amsterdam-based EMA’s Safety Committee was meeting Tuesday to assess new information and would reach a conclusion at a special meeting on Thursday, Cooke said. 

For such a rare side effect (if side effect it is) it seems unlikely, given the EMA’s preliminary reassurances, that there will be any change in the approval of the vaccine for those at high risk from COVID-19, such as the elderly, health care workers and those with underlying conditions. More likely is that any risk identified will be flagged, just as a similar rare blood-clotting risk is flagged for women who use the birth control pill. France and Italy have already indicated that they are ready to resume the rollout as soon as the EMA gives the green light.

But might there be a change in the advice for those at low risk – the healthy under-50s – if side effect it turns out to be? Younger women appear to be particularly affected, according to the German data, possibly for hormonal reasons (as with the pill, and with pregnancy).

With a vaccine as hurried out as this one (and all the Covid ones), it is almost inevitable that rare side effects are going to show up when we vaccinate millions that wouldn’t have shown up in the trials when we vaccinated thousands. This may well turn out to be a false alarm. But that doesn’t mean we should assume no rare side effects will emerge as the rollout continues. As Ross Clark writes:

This week’s war of words over AstraZeneca shows just how foolish it is to pretend there is a scientific consensus on the safety of vaccines, or indeed anything else. If we want people to have faith in vaccines – and Britons have shown great faith so far – it will be necessary to be open about any risks which emerge, however small those risks may be.

Let’s hope on Thursday, as widely expected, the EMA finds that it was just a statistical coincidence with no connection to the jab. That would clearly be the best outcome for everybody.