Let us hope that antibody response, as measured, is a good measure of effectiveness - short and long-term.Large study shows just how effective the vaccines are at developing antibodies against Covid. After the first jab 96% of Britons had them, and after the second that figure went up to over 99%. The average age of the participants was 65 and all were tested for the antibodies prior to be given the jab, anyone who already had the antibodies was not included in the trial. More details here.
96% of Britons develop antibodies after one Covid jab, study finds | Coronavirus | The Guardian
Also, I'd like to know how antibody responses relate to side effects, if at all.
Overall there appears to be some truth in the claim that many who had AZ had worse side effects from first vaccine than second. Whereas for Pfizer it has often been the other way round.
We had AZ. I had very minor effects - no worse than could happen just because you don't feel 100% one day. Partner felt very poorly for a couple of weeks or so after the first. Did I almost immediately produce antibodies so fight it off quickly? Or was it her immune system being very effecient that made her feel so bad? Or neither!