That crucial consideration is: the health of un-vaccinated people around me. If there are people around me who will not be eligible for a vaccine for months, THEY seem to be better protected - from me - if I choose either of the two higher-efficacy vaccines (within a "reasonably short" incremental timeframe).
Based on the data we have so far it looks like I am about 5x more likely to get infected after J&J compared to Pfizer/Moderna, based on J&J's lower efficacy of about 75% vs 95%.
Even though J&J would protect ME from serious complications, if I get J&J and then get infected I am contagious, and therefore I am a risk to still-unvaccinated people around to me who still have normal risk for serious/fatal complication.
So if I can expect to have Moderna or Pfizer available within a "reasonably short" time frame, I'll wait for one of those higher-efficacy vaccines in order to better ALSO protect the unvaccinated people around me.
But the hard part is deciding what is a "reasonably short" timeframe? There is obviously a non-zero incremental risk from waiting, so that short-term risk (to me and mine) needs to be balanced against the longer-term risk (to others) from my rushing to accept a less efficacious vaccine sooner.
Using the current daily covid infection rate divided by the population as a rough, quick, back-of-envelope guesstimate for "incremental daily risk of infection" on the order of 0.015%.
Pretty big assumptions. But unless my reasoning is way off, I'll be willing to wait an extra 10-14 days for Pfizer/Moderna (vs J&J) with the goal of lower net risk to the unvaccinated people around me.
