Drug regulatory agencies have to take a cautious approach. They are the last line of defense against toxic or adverse side effects in new drugs that are just beginning to be used widely. All modern countries in Europe, North America, Asia, and elsewhere have laws regulating new drugs.
This is no known link between vaccines and blot clotting. That is to say, there is no known link between the biological processes of immunization and blot clot formation, as we now understand them. So, in theory, it shouldn't happen. Likewise, no database has evidence of such links. We have not identified such a link in previous cases. So, in practice as well as in theory, it shouldn't happen. But that does not mean that we can rule it out as impossible. That's where drug regulatory agencies do their work. I see nothing wrong with temporarily stopping vaccinations while they look into the existence of a previously unknown or unrecognized link. They would be negligent if they failed to do this.
I sometimes wonder what it would be like if the same rigorous regulatory approval process that new drugs must pass, was applied to other industries. Imagine the uproar if airplane or automobile manufacturers had to run the equivalent of large clinical trials – before they could sell any new product. What if Boeing had to perform rigorous tests of a new commercial airliner, such as the 737 Max, and then submit all their data to an agency with real legal & law enforcement powers before they could ever sell their new airliner? Same for General Motors, Ford, Chrysler, Toyota, Honda, etc.
I wish people would stop complaining about this. (Irv, I'm not singling you out. TLS Guy is the lead offender at this.) This is nothing like the corrupt French or East German Figure Skating judges at past Olympics. The European nations have an absolute right as well as a legal & moral responsibility to investigate such problems before they become a widespread hazard.
I'm unrepentant, because this bureaucratic thinking will cost lives, and lots of them.
These are the facts.
According to the charity Thrombosis UK, up to one in 1,000 people each year will experience a dangerous blood clot in a vein, known as a venous thrombosis. That means about 66,000 people in Britain might be expected to suffer a blood clot annually – or 1,269 a week.
According to AstraZeneca, there have been 15 events of
deep vein thrombosis (DVT) and 22 events of pulmonary embolism (PE) reported among those given the vaccine so far across the EU and UK, based cases up to March 8.
The company estimates that 17 million AstraZeneca vaccines have been delivered in that time. That means that the risk of suffering from DVT or a PE after vaccination is 37 in 17 million, or roughly one in 460,000.
At the current prevalence rate, in a population of 17 million we might expect 326 cases to naturally show up in the week following a vaccine, so 37 starts to look very low.
The National Institute for Health and Care Excellence (Nice) estimates the risk of a blood clot is even higher - around one in 500 - meaning that even more cases would be expected.
Even if all 37 cases were linked to the vaccine – which is highly unlikely – the risk is still far lower than that of dying from coronavirus, which has an infection fatality rate of between 0.5 and one per cent.
Dr Peter English, the immediate past chair of the BMA Public Health Medicine Committee, said: "When a vaccine is administered to millions of people, it is inevitable that some adverse events, that would have happened anyway, will happen shortly after vaccination.
"It is most regrettable that countries have stopped vaccination on such 'precautionary' grounds. It risks doing real harm to the goal of vaccinating enough people to slow the spread of the virus, and to end the pandemic."
Another factor that must be taken into account is the characteristics of the vaccinated population.
Both DVT and PE are most common in people aged 50 and over, as well as those with underlying health conditions and those who are overweight or obese. In other words, they are most common in the very population which is being prioritised for the jabs.
For people under 40 years the annual incidence a blood clot is 1 in 10,000, whereas for people over 80 years the incidence rises to 1 in 100.
Jo Jerrome, the CEO of Thrombosis UK, said: "We need to remember the risk of DVT/PE increases with age and that we are currently vaccinating the very oldest in our population.
"If the figure is 37 per 17 million, who will be mainly over-60s, we think this is very low and less than the background risk associated in the general population, so would agree with current statements from the Medical and Healthcare products Regulatory Agency and the WHO that there appears to be no association."
In Britain at least, the numbers of incidents of DVT and PE do not differ between the vaccines.
Michael Makris, professor of Haemostasis and Thrombosis at the University of Sheffield, pointed to reports showing that there have been 13 cases of pulmonary embolism in 10 million doses of the AstraZeneca jab, and 15 cases in the
Pfizer/BioNTech vaccination.
And there is one more possibility. Blood clotting is very common in people suffering from coronavirus itself, so the figures could be picking up people who caught the virus around the time of vaccination.
Stephen Evans, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, said: "Coagulation disorders are very common in patients with Covid-19. Early reports from China noted over 30 per cent of patients reaching hospital had thrombocytopenia.
"Unless we are sure that those who suffered these unfortunate events very definitely did not have Covid-19, then it would seem to be premature to suggest it was the vaccine that caused these events."
Ronan Glynn, Ireland's deputy chief medical officer, said it was important to halt the vaccinations as a precaution but admitted the country may be overreacting. "It may be nothing," he said on Sunday. "I sincerely hope that in a week's time we are accused of being overcautious."
But a week is a long time in a national vaccination programme, and such a pause may come with consequences. Let us hope lives are not lost because of this overreaction.
What has been occuring in continental Europe is just pure folly and can be quickly shown to be extremely harmful. Physicians have to assess risk on a daily basis. Many are difficult, this risk assessment on the other hand is easy.
The British regulator has not, and does not, intend to stop vaccinations proceeding apace, and that is the correct decision.
