As far as I know, all of the vaccines have been through the requisite trials,. I remember reading the progress of them last year.
Fact check: COVID-19 vaccines did have clinical trials
The default vaccine here in NZ is Pfizer. I have had my first shot and my 2nd will be in a week. My hubby just got his second today. My 13 year old son has his first appt for mid September.
We are relieved that the vaccine rollout here is finally ramping up. They were doing it in stages with the elderly, border, health workers being covered first. We have had issues with supply, but that appears to be over now. I wish we could have had a quicker rollout but being a small isolated country with low transmission, we weren't high on the priority list, I think in terms of distribution. We don't have the facilities to manufacture our own.
In terms of side effects, both of us have only experienced an achey heavy arm so far. I am told the 2nd dose might hit harder. But I'd rather have a few days of flu symptoms than the possibility of hospitalization, intubation, ventilator, death. That's not even factoring in long haul COVID and the possibility of permanent damage to the lungs, heart, neurological system etc.