Barts-MS rose-tinted-odometer: ★★
In response to a comment from one of our readers. We have not directly addressed the thrombosis AstraZeneca vaccine issue as we are not vaccinologists or haematologists. But as there seems to a lot of anxiety around this issue a short blog post about the potential risks may allay your fears.
I received the following email, from Professor Marcel Levy (Consultant Haematologist and CEO, UCLH), on the 19th of March that suggests the underlying thrombotic disorder that has been recognised in patients who have received the Oxford-AstraZenca COVID-19 vaccine may be quite specific and identifiable.
I am taking a rather peculiar step but I think it is important to get this premature information out in the open for the potential benefit of patients.
We have found a strong clue about what is causing the rare thrombosis and thrombocytopenia in patients who received the COVID-19 vaccination. We have to be extremely careful because it is pending some more confirmation but there may be immediate implications for patients we cannot ignore. I know some others may be thinking in the same direction but are awaiting to publish the findings in a journal but we feel it takes too long and I think it is not responsible not sharing this with others as soon as possible.
We have identified three UK cases who developed rare (cerebral sinus vein) thrombosis in London after COVID-19 vaccination and Marie Scully of UCLH has identified a very strong anti-platelet factor 4 antibody response in those patients. They were not exposed to heparin before but you may realise Ted Warkentin has described incidental cases a few years ago (Warkentin TE, Basciano PA, Knopman J, Bernstein RA. Spontaneous heparin-induced thrombocytopenia syndrome: 2 new cases and a proposal for defining this disorder. Blood. 2014 Jun 5;123(23):3651-4.). We feel it may be a good idea if others are confronted with these patients to do a HIT-ELISA and to withhold heparin until we know whether this is real or a false lead and awaiting further confirmation.
Just want to emphasise that we all realise this is extremely rare and should not be a reason to stop vaccination whatsoever. However, when confronted with a case, this may have consequences for their optimal treatment.
Please feel free to share this information within your communities as you may seem fit, as it might have implications for patients (once again, I think we need to be very careful of course before jumping to conclusions). I know we all want to be the first to publish, but we also have a responsibility for our patients.
All credits to Marie Scully who has done this test in these patients and is happy to share with everyone.
Best wishes, Marcel Levi
Prof. Marcel Levi MD PhD FRCP
Professor of Medicine, University College London
Professor of Medicine, University of Amsterdam
Consultant in Acute & Vascular Medicine and Haematology
Although we can’t be sure these thromboses are due to the AstraZenca vaccine it seems increasingly likely that they are as these sorts of thromboses have not been seen (yet) or described with the Pfizer-BionTech and other COVID-19 vaccines. According to the latest figures from the MHRA, there have been 22 reports of a blood clot or thrombosis in the brain called cerebral venous sinus thrombosis (CVST) accompanied by a low platelet count (as described in the letter above) as well as eight reports of other blood clotting problems with low platelets, among recipients of the AstraZeneca COVID-19 vaccine. Of these 30 reported cases, seven people have died. The denominator is over 18 million people who have received the vaccine. At the moment the rate of this complication is 1.7 people per million vaccinated and one death for every 2.6M people vaccinated. These estimates are likely to be under-estimates because of a reporting lag, but even if the risk increase by a factor of 2 or 3 they will still be relatively low. This risk needs to be compared to 1 in 1000 chance of dying from COVID-19 if you are aged between 40 and 50 years of age.
You have to realise that when you are vaccinating the whole adult population shit is still happening in the background; i.e. people will be getting DVTs, pulmonary emboli, myocardial infarctions, pneumonia, Bell’s palsy, strokes, CVSTs, etc. Life and biology continue as normal and all that has changed is that a vaccine is added to the mix. So when the EMA and MHRA say the benefits of these vaccines, including the AstraZeneca vaccine, outway the risks they mean it and their advice is based on safety data from tens of millions of vaccinated adults and a risk:benefit analysis. The latter is a judgment call they make on the impact of COVID-19 at a population level vs. the population benefits of vaccination. Their message can’t be any clearer: #GetVaccinatedASAP and these #VaccinesAreSafe. I think these figures speak for themselves and I fear we are literally throwing the baby out with the bathwater by dismissing the AstraZeneca vaccine as being too risky to use in certain population groups.
If you have any doubts about the benefits of being vaccinated or not being vaccinated just look at what is happening in France and Germany at the moment compared to the UK. My question is how many extra deaths are going to have happened because of delayed vaccinations in these countries? I suspect orders of magnitude more people will die from COVID-19 than from the rare complications of the COVID-19 vaccines. Do you agree?