Well, since only the mRNA vaccines are available now, I'd have zero hesitation getting either. Once other ones get approved, I'd then have to see what the data say. However, I'd certainly take 95% efficacy of either mRNA vaccine over the 60-90% efficacy (and remaining clinical questions) of the AZ one if I had a choice, but if I were in the UK where they likely have a lot more of the AZ vaccine, I'd get that over nothing, unless I knew my exposures were negligible. Many of us will have multiple choices in April, when I expect vaccinations to open up to anyone interested and at that point, I'd have to see what all the clinical data look like, but certainly, so far, the mRNA vaccines look best - but if we get one that's just as effective with a single shot (like the J&J one), I'd probably get that one, assuming safety isn't an issue.