It's "viral vector vs mRNA".
Do a search on the quotes and it should give you plenty of information. As far as I remember it was naysay'd early and then recontinued and then naysay'd again.
My minimal "research" (reading articles) hasn't shown anything ridiculously higher with clots vs the other two mRNA compounds but maybe it's demonstrable. Call a doctor if you are concerned but sometimes just educating yourself on what to look for with blood clots and being ready to jump in the car may be your only real option because it's not like it's guaranteed (probably in the rare category). As with most things regarding this, there is a shocking amount of laxity regarding valuable information being disseminated to the public so looking into this deeply is a challenge. If you hit some roadblocks maybe I could look for a few good peer-reviewed journals to ease your mind a bit but I sift information a bit differently than most and to translate what I find useful with quoting and sources and so forth would take me MANY hours to post publicly. I also haven't seen many people that look into viral vector tech NEARLY 1/10th as much as mRNA compounds. I'm not sure why this is.
I do think it's interesting that it is a 3rd option for people that are against mRNA compounds and yet feel pressured to get them. Also 1 injection vs 2.
It's efficacy is also reportedly less. I did a bit of internet browsing on it some while back and it is interesting to look into. Not just because of it not fitting in with any of the rhetoric but also its history.
I had also understood that the 2nd (for J&J) and 3rd (for the 2 other companies) you could get any one of them. I am uncertain why that is, so you may want to look into it further.
Note: I am not saying I am for this technology in any way or telling you not to be wary of the risks, neither am I "hyping" them or saying it is incredibly risky. It is unclear to me.
I feel like this company getting all the bad press about clots is odd because I had thought there were similar risks with the other two companies producing viral compounds but perhaps there is more and I just don't want to sift through the morass of articles saying little on the topic beyond conjecture.