Poor Astra-Zeneca. The covid-19 vaccine that they had hoped would generate an endless tide of goodwill is instead turning in to one long public relations disaster. First it was the case of transverse myelitis that caused them to have to halt their vaccine trial temporarily. Then it turned out that they had given the wrong dose of vaccine to a bunch of participants in the trial. Then, when the preliminary trial data was published, the vaccine only appeared to be 70% effective at preventing covid-19, while vaccines by competitors Pfizer and Moderna were more than 90% effective. And now, perhaps worst of all, it appears that their vaccine has killed several previously healthy young healthcare workers. Poor poor Astra-Zeneca.
I am, of course, being facetious.
Let’s get in to the weeds of what’s actually happened with the Astra-Zeneca vaccine. But first, we need to discuss two rare diseases.
Cerebral venous sinus thrombosis is a condition in which a blood clot has formed in one of the veins that drain blood from the brain. Since the blood is not able to move forward through the vein, it gets stuck. This often results in a stroke (the death of part of the brain due to a lack of oxygen). Cerebral venous sinus thrombosis is very rare, occuring in roughly one in 300,000 people per year.
Heparin induced thrombocytopenia is an auto-immune disorder that sometimes occurs in people who are being treated with an anti-coagulant drug called heparin. Thrombocytopenia literally means “lack of platelets” (platelets are cells in the blood that form blood clots, in order to prevent bleeding, when a blood vessel is damaged). What happens is that the body starts to produce antibodies against platelets, which causes the platelets to bind to each other, forming blood clots. Since most of the platelets end up bound to each other, you no longer see very many free floating platelets in the blood stream, which is the cause of the thrombocytopenia.
And having lots of blood clots in the circulation is a very bad thing. If they get stuck and block off the flow of blood somewhere, then some part of the body starts to die. If they block off flow to part of the brain, the person has a stroke. If they block off flow to the heart, the person has a heart attack.
Thankfully, heparin induced thrombocytopenia is rare, which is why the drug is still used in clinical practice. And the condition doesn’t occur spontaneously in people who haven’t recently received heparin. You need to receive heparin in order to develop it.
Although people with heparin induced thrombocytopenia often develop clots in their blood stream, it is unusual for those clots to form in the cerebral venous sinus. So it is extremely uncommon for a patient to develop heparin induced thrombocytopenia in combination with a cerebral venous sinus thrombosis. In fact, it’s so uncommon that only a handful of cases have been reported in the entire medical literature. Up to now, that is.
And like I said, heparin induced thrombocytopenia only develops in people who have received heparin. In people who haven’t received the drug, the odds of developing the condition are precisely zero.
Two case series were published in the New England Journal of Medicine this week. A case series is basically just a collection of case reports, that have been gathered together in to one article because they are similar in some important way. The first case series comes from Norway. It concerns five patients who became acutely ill between seven and ten days after receiving the Astra-Zeneca vaccine. The patients were health care workers aged from 32 to 54 years old. All were fundamentally healthy before receiving the vaccine. One had mild asthma, and another had high blood pressure.
All five developed thrombocytopenia. Four out of the five developed cerebral venous sinus thrombosis (the fifth had clotting in veins at the base of the skull and in the abdomen instead). Three out of the five died. By the time these cases reached the Norwegian authorities and the dots were put together that this might have something to do with the Astra-Zeneca vaccine, 132,000 people in Norway had received the Astra-Zeneca vaccine.
So four people out of 132,000 who received the Astra-Zeneca vaccine developed the normally exceedingly rare combination of thrombocytopenia with cerebral venous sinus thrombosis. All had received the Astra-Zeneca vaccine seven to ten days earlier.
Yes, I agree, that is quite suspicious.
The second case series comes from Germany. It concerns eleven patients, aged from 22 to 49 years, who became ill between five and 16 days after receiving the Astra-Zeneca vaccine. Like in the Norwegian case series, all of the patients had thrombocytopenia, and at least nine of the eleven had cerebral venous thrombosis. Six of the patients died.
Blood from both the Norwegian patients and the German patients was subsequently tested for the type of antibodies that are typically seen in heparin induced thrombocytopenia. Every single test came back positive. Note that none of these people had been treated with heparin before the onset of symptoms, and several didn’t receive any heparin at any time point during their hospital stay.
Case series are considered to be one of the lowest tiers in the hierarchy of scientific evidence. Normally I wouldn’t bother to write an article about a case series. But here we have a constellation of signs and symptoms that is so uncommon that it’s previously only been described a handful of times in the medical literature, occurring again and again after a very specific exposure. Therefore, even with just two case series to back the claim up, we can be pretty certain that the Astra-Zeneca vaccine is the cause.
So, to conclude: yes, several young, otherwise healthy people have been killed by the Astra-Zeneca vaccine.
The incidence of this condition appears to be quite low. As mentioned, 132,000 people had received the Astra-Zeneca vaccine in Norway when this was discovered. And at least five of those people developed this new disease state, which the authors of the case series are calling VITT (vaccine induced thrombotic thrombocytopenia). If we assume (generously) that every case of vaccine side effects gets reported, that would mean an incidence of around one in 26,000.
However, the system for reporting of vaccine side effects is entirely dependent on three separate steps, and the system can easily fall down at any of the three steps. First, the treating clinician has to know that the patient has recently received a certain vaccine. Second, the clinician has to consider that the patient’s condition might have been caused by exposure to that vaccine. Third, the clinician has to take the time to contact the relevant authorities.
It is well known that most side effects never get reported. So what we are witnessing here could easily just be the tip of the iceberg. As societies, we’ve rushed headlong in to mass vaccination campaigns based on scant evidence. Most people seem unaware that the covid-19 vaccines have been approved based on only two months of preliminary trial data, and that the vaccine trials are still ongoing, and won’t be completed until 2022 at the earliest.
These case series show that a number of previously healthy young people have so far been killed by the Astra-Zeneca vaccine. Considering their age and underlying health status, the risk to them from covid-19 itself was infinitesimal. For healthy young people it is not at all clear that the potential benefits from the covid-19 vaccines outweigh the potential harms.
That doesn’t just go for the Astra-Zeneca vaccine. It goes for all the vaccines. It is quite possible that new revelations will arrive over the coming months concerning the other vaccines too. Now would be a good time for governments to change vaccination strategies, halt all plans to vaccinate healthy young people, and instead only vaccinate those who are at substantial risk of serious outcomes from covid-19.
It is unethical to vaccinate healthy young people until it is clear that the benefits to them outweigh the harms. At the present point in time, that is not at all clear.