Oxford vs. Pfizer - why are people waiting to get the Oxford Vaccine?

[Raccooons]

Apologies if this has been done already, I had a quick look and couldn't see that it had previously been discussed (if it has, please feel free to direct me to the existing thread).

I'm frontline NHS and my trust has received their delvery of the Pfizer/BioNTech vaccine. It should be offered to me in the coming weeks and I'm very excited about this. I am slightly vulnerable due to being overweight, but otherwise healthy with no allergies or sensitivities to medicines.

I have read about the scientific differences - Pfizer/BioNTech has slightly higher overall efficacy (95 vs 90% when given in the dosages they are licensed for)... Oxford/AstraZeneca can be stored more easily whereas Pfizer is no good if not stored at minus 70 degrees C... Pfizer uses mRna whereas Oxford uses weakened virus.

But I haven't seen anything that places one in favour of the other, clinically. As far as I have read, it seems they haven't been tested "head to head" - so why are there people declining the Pfizer vaccine and choosing to wait for the Oxford vaccine? Are there unpleasant or serious side effects of the Pfizer one that I don't know about?

Is it just people being nationalistic - one Doctor quoted that people were saying "We want to wait for the English one"?

You will be told- you get a card with it on including the batch number.

My parents had the Pfizer one today. I’m very grateful that they got an appointment and were able to have it done. I’m a TA and also have an auto immune disease, when I eventually have mine done I think I’d need to have the Oxford one because it’s better for auto immune conditions? I don’t quite understand the science behind it but I’m more scared of having a massive flair up than I am of Covid tbh so I’d really like the one that won’t make me ill (and yes I do appreciate I’m lucky if I get one at all).