Janssen has finished recruiting for their 1 dose Phase III trial, but is still doing that for their 2 doses 8 weeks apart trials, this huge one https://clinicaltrials.gov/ct2/show/NCT04614948 and this small one in the US and Belgium https://clinicaltrials.gov/ct2/show/NCT04436276 There reporting on their one dose trial's efficacy results is pretty good, about what I expected, so if this gets you that one first dose ASAP its seriously worth considering. It's also a relatively mature platform, used previously for their Ebola vaccine which passed an European Phase III trial, but wasn't the earlier one that made such a difference in the last outbreak.
The other vaccines you might get are less mature platforms, AZ/Oxford 2 doses 21 days apart has less efficacy than Janssen's 1 dose (Oxford had not before 2020 ever tried testing their platform on more than 40 people at a time), the mRNA vaccines I'm sure you've heard all about, but I wouldn't make any bets on when Pfizer will be able to provide you a dose from their currently? closed Belgium plant.
The other vaccines you might get are less mature platforms, AZ/Oxford 2 doses 21 days apart has less efficacy than Janssen's 1 dose (Oxford had not before 2020 ever tried testing their platform on more than 40 people at a time), the mRNA vaccines I'm sure you've heard all about, but I wouldn't make any bets on when Pfizer will be able to provide you a dose from their currently? closed Belgium plant.