Hi, scientist here again. This wall of text will be much smaller compared to last time.
The latest update from the EMA (european medical advisory board) on the AZ vaccine is here for your reading pleasure:
https://www.ema.europa.eu/en/documents/covid-19-vaccine-safety-update/covid-19-vaccine-safety-update-vaxzevria-previously-covid-19-vaccine-astrazeneca-29-march-2021_en.pdfHere are some key takeaways from this pdf:
1. There was no evidence of a problem with manufacturing or product quality related to the vaccine batches specified in the case reports.
2. Overall, the number of cases of embolic and thrombotic events after vaccination reported to EudraVigilance (see section 3) in relation to the number of people vaccinated
was lower than the rate of such events in the general population3. However, Vaxzevria could possibly be associated with very rare cases of specific embolic and thrombotic events.
4. In the reported cases, including some that resulted in death, these events occurred within 14 days after vaccination. They occurred mostly in people under 55 years of age, the majority of whom were women. However, these patient characteristics could reflect the higher proportion of such individuals offered Vaxzevria invaccination campaign.
5. Such imbalances in numbers of cases between the general and vaccinated populations were not visible for the older age groups.
6. A causal link of DIC and CVST [The rare cases mentioned in point 4] with the vaccine is not proven but cannot be excluded and
requires further investigation.
Quote (SharpNips @ Mar 30 2021 02:35pm)
Correlation is not causation
this
7. Based on all available data on embolic and thrombotic events, PRAC considered that the benefits of Vaxzevria in preventing COVID-19 and related death
continue to outweigh the risks, and that
this vaccine can be used while further data collection and assessment are ongoing.
It's important to note that they also advise people with certain symptoms (shortness of breath, chest or persistent abdominal pain, leg swelling, severe or persistent headache, blurred vision, persistent bleeding, and skin bruising or round, pinpoint spots beyond the site of vaccination appearing after a few days) to go get medical attention to address the rare disorders. It is also good to know that there is testing and treatment available to the small amount of people that wind up suffering from this. It can be treated successfully if caught in time.
These events of rare blood clotting disorders are occurring in clusters in various countries, which makes it hard to pin down a causative role of the vaccine. The female sex variable is also noteworthy, as that is a large variable in the rare allergic reactions to Pfizer-Biontech and Moderna vaccines. It's also noteworthy because of whether or not the use of birth control might involved (which increases the risk of blood clots).
Let's contrast all of this with the seasonal flu shot. Few people develop a rare neurological disorder after the seasonal flu shot called Guillain-Barré syndrome, and the US's CDC describes the causative role of the flu vaccine in this as "variable and inconsistent," which makes things difficult to understand scientifically. All of this to say that it's going to be difficult (but technically possible) to establish definitive causative links with respect to the AZ vaccine and blood clotting disorders. It should be investigated, of course. All this occurs at such a low rate that it's unlikely it would have popped up during clinical trials, so this is why we're all going through this now and not back then.
The slowdowns/pauses are likely being done to maintain public confidence (we hit pause and looked into it, so we can be comfortable when we resume), which is going to have the opposite effect by making people think that something is "wrong" with the AZ vaccine. EU/CA governments can be transparent about what's going on and keep the populace updated without doing away with scientific advisory per the EMA. Individual governments are acting outside of EMA consensus in the EU. Canada is free to do as they please, but at a human and political cost. Since the EU (and CA to a lesser extent) are largely reliant on the AZ vaccine, this is going to prolong the pandemic. No sympathy for AZ themselves, as they've screwed up clinical trials all throughout the pandemic.
Go Avs.