So the early research seemed to suggest that if you were blood type O or Rh neg you had some kind of natural immunity to covid - you were less likely to catch it in the first place and you were less likely to get severe covid.
Conversely if you were blood group A or AB you were more likely to get severe covid
Whats interesting on this thread is that Pfizer recipients are definitely reporting less symptoms. I've heard that AZ is worse for the first jab but ok for the second but the reverse is true for Pfizer, so its possible that the Pfizer recipients just haven't had a second dose.
The other thing thats noticable is the sheer number of ABs on here. Myself included, and why I started the thread (its on my maternity notes).
If blood type O is giving a sight protective effect and blood type A puts you at slightly higher risk then thats interesting (remember if you are blood type A you can either be effectively AA or AO so may have some protection from a recessive O gene.) The AAs and the ABs may be the unlucky ones with their immune systems working in different ways which aren't great with covid but you'd perhaps notice it more amongst the ABs slightly because half the blood type A would be better off AOs.
Blood type B is fairly uncommon in the UK (8% of the population) but they are seem to be under represented on this thread.
Blood type O is the most common blood group (38% of the population). Its about a 50/50 split between those who had AZ who had not much more than a sore arm and those who had flu symptoms, sickness or more.
Blood type A is 32% of the population. More of the A+ group seemed to feel more ill than the O group.
But yes the AB group - particularly the AB+ is definitely overrepresented (AB is 3% of the population). Notably there were only 3 ABs who had Pfizer - the rest were all AZ. And the AB+ seemed to be split 1/3 mild symptoms to 2/3 who felt a lot more ropey.
Now this isn't good methodology by any means and its certainly not a big sample, but it does give me some food for thought. What is going on with the ABs??!
Thanks to everyone who contributed. I really would like to see more research on this being done properly.