Coronavirus: Blood clot vaccine fears have to be set in context of Covid risk

According to sources who spoke to the Reuters news agency, Italy's decision follows the deaths of two men in Sicily: one was 43-year-old Navy officer, Stefano Paterno, who died of a heart attack the day after being inoculated; the second was 50-year-old policeman Davide Villa, who reportedly fell ill within 24 hours of his vaccination and died 12 days later with a deep vein thrombosis.

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In Austria, a 49-year-old nurse died of "severe clotting issues" 10 days after being immunised.

All three are known to have been inoculated using vaccines from AstraZeneca’s batch ABV2856, which sent one million doses to 17 countries.

Denmark, along with non-EU Norway and Iceland, have gone further, pausing the entire rollout of the Oxford vaccine, while Thailand - where the vaccine drive was supposed to get underway yesterday - also cancelled it.

Rates of Covid are higher in France and Germany than in the UK, where more than three times as much of the population has been vaccinated

For now, France, Germany and Spain are continuing to use it, but uptake has been sluggish and seems unlikely to improve with a fresh wave of suspicion now thrown in.

The alarm has taken hold in what was already fertile territory for hesitancy bordering on hostility towards the Oxford jag in Europe, with scepticism fostered by the countries’ own leaders.

Everything from a long history of vaccine distrust in France and Italy (in a poll in December, just 40 per cent of French citizens said they intended to get vaccinated against Covid), to post-Brexit resentment towards the UK has been blamed.

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Problems with the Oxford vaccine started in January, when a German newspaper quoted a minister claiming that the jag was “only eight per cent effective in the elderly”, a blunder cemented days later when the German government decided against giving the vaccine to over-65s on the grounds that there was "insufficient data" for its effectiveness.

Even German Chancellor Angela Merkel - a scientist before she entered politics - declined to take the Oxford vaccine despite backing from the World Health Organisation, while French President Emmanuel Macron said it was "quasi-ineffective" for people over 65.

These doubts were difficult to reverse in the popular imagination even before the latest worries about blood clotting.

Volunteers wait for people to come to a vaccine hub in a former airport in Berlin

At some vaccination centres in Berlin where only the Oxford vaccine was available, it was reported that fewer than 200 people were turning out for the 3,800 available appointments.

Potentially life-saving vaccines were literally being left on the shelf.

To date, Germany and France have each vaccinated around 10% of their populations compared to around 35% in the UK.

France has more than three times the rate of Covid compared to the UK and cases are climbing; Germany's Covid rate is currently 13% higher than the UK's and yesterday the country's leading public health body, the Robert Koch Institute, warned that it has now entered its third wave.

Will this be enough to turn the tide of public opinion in favour of accepting the Covid vaccine amid belated assurances from their governments that it is safe and effective?

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A Public Health Scotland study in February revealed "spectacular" results showing that the Oxford vaccine reduced hospital admissions by up to 94%, compared to 85% for the Pfizer jag favoured by Europeans (its co-developer is German pharmaceutical firm, BioNTech).

Despite this, and assurances from the European Medicines Agency that there is no solid evidence of a causal link between the Oxford vaccine and blood clots and that its “benefits continue to outweigh its risks”, history has taught us that vaccine scares are like a Pandora’s box: once opened they are close to impossible to contain again. Just look at the MMR scandal.

Consider that around five million Europeans have already received the AstraZeneca vaccine, and against this, three deaths and fewer than 40 “thromboembolic events” - that is, developing blood clots - have been recorded.

Importantly, there is no evidence that this is anything more than a statistical coincidence: in any given population at any time (particularly the elderly whose age alone puts them at increased risk of strokes and who are also the group prioritised for vaccination) clots would be expected to occur naturally.

Vaccination centre at Rome Airport. Italy has suspended the use of some of the Oxford vaccines after two deaths in Sicily

Against this, consider that current UK data indicates that 10% of people who test positive for Covid are hospitalised (the true figure is likely to be lower as asymptomatic and mild cases will be missed), and that one in three patients admitted to hospital with the disease develop blood clots.

In a population of five million people where everyone was infected with the coronavirus, this would be expected to result in an astonishing 167,000 thromboembolic events - more if you adjust for the majority of those people being over 65.

Even if you cut that by 66% to assume - generously - that two thirds of cases are asymptomatic and never detected, that still leaves nearly 56,000 clotting events.

On average across the EU, around one in 10 people have had a single vaccine dose compared to 35% in the UK and 40% in Scotland

In the UK, more than 11 million doses of the Oxford vaccine have been administered with no abnormal spike in deaths or blood clots.

The number which has occurred is within the parameters of what would have been expected to occur naturally in a similar population, over the same time period, pre-Covid.

This is why, while it is important that these cases are investigated and any link to a potentially faulty batch probed, they must also be set in the context of the very real danger from Covid.

As Professor Stephen Evans, an expert in pharmaco-epidemiology at the London School of Hygience and Tropical Medicine, put it: the “super cautious” decision to withdraw the vaccines could be justified if there was an abundant supply of alternatives - but was a “mistaken use of precaution” if it delays vulnerable people from being vaccinated against a disease which has claimed more than 876,000 lives across the continent since February 2020.