Latest on the Oxford AstraZeneca vaccine
Written this evening of Tuesday 16 March. Story will evolve over the coming days, will try to keep this up to date.
Short summary — There’s currently no obvious reason for concern around any COVID-19 vaccine, including the Oxford AstraZeneca candidate. When you’re in the queue, do accept any flavour of vaccine you’re offered.
Why have several countries suspended the AstraZeneca vaccine?
Small safety signals that warrant investigation. But you can investigate vaccine safety without stopping the rollout. I just can’t see any reason to justify suspension.
So, what’s going on?
There’s a safety signal of possible adverse events. Data is in short supply, but Germany have today clarified their situation. 7 cases of blood clots that have caused concern, which occurred soon after the individuals had received the vaccine.
Anything in it?
Probably not. Tiny numbers of cases being reviewed. Vaccine roll out is in vulnerable populations that have many existing co-morbidities.
And, correlation does not equal causation, as we nerdy types say in the epidemiology world. Maybe you had porridge this morning, and this evening your Auntie Mildred phones you. There’s a correlation for you. But are the two events causally linked? You’d assume not (and if they are, your family-based anecdotes are just too dull for me to listen to you, I’m so sorry)
But less flippantly, when you’re vaccinating a worldwide population of 8 billion people with 2 doses of a vaccine, among those 16 billion-ish doses there will naturally be clusters of coincidences. Particularly when you’re vaccinating older or more vulnerable populations who are more likely to have conditions that make them prone to blood clots.
Also worth noting that COVID-19 infection itself causes blood clots (link below). And there’s plenty of that virus hanging around in people in France, Germany etc right now.
So, it’s right that the signals are investigated as they happen. But, leaving people unprotected against COVID-19 to investigate these very small safety signals is something I find baffling.
Politics involved?
I hope not. Though the AstraZeneca vaccine has been a bit of a political football over the last few weeks. For reasons I don’t understand, since safety and efficacy profile is excellent.
Safety is excellent? Prove it
Fair enough. See the latest from the MHRA (UK regulator) that covers real-world data totalling 10 million doses of the AstraZeneca vaccine. For example, the ‘overall safety experience with both vaccines is so far as expected from the clinical trials’.
And the phase 2 and phase 3 clinical trials also suggested a highly safe and effective vaccine (see here and here).
And there’s also the AstraZeneca statement, covering 17 million doses across UK and EU. No signal spotted (and indeed rates were lower in the vaccinated populations).
What happens now?
Waiting on the European regulators, the EMA, to provide a final update to their investigations on Thursday. But note that the EMA have both yesterday and today reiterated their support for the vaccine and emphasized they have not seen anything to concern them. As have the WHO, and the MHRA, who have put out new statements this week.
Hopefully, in next few days, all countries will reinstate this vaccine back into their roll-out.
Hang on, you not going to mention the International Society on Thrombosis and Haemostasis?
Oh my, I nearly forgot about them, thanks for reminding me! They know tons about blood clots and stuff like that. They recommend continuing to have the AstraZeneca vaccine.
Problems with vaccine hesitancy?
Quite possibly, and therein lies the concern. It can take days to wreck confidence in a vaccine, and then months or years to rebuild it. If people decline AstraZeneca and wait on Pfizer being available, then there’ll be more COVID-19 than there needs to be. And that brings in prospect of need for further lockdowns, new variants, and so on.
So in conclusion?
If you’re eligible, get vaccinated, with any vaccine, unless your GP recommends otherwise. And then hopefully we can bring forward the time we can safely go to the pub.
