I would also be happy to have gotten the J&J. For us, it was whatever we could get first, brand didn’t matter.
Interesting, though, that a recent article in the NEJM states that almost full immunization is acquired with the first dose of either the Pfizer or Moderna vaccines by the time the second booster dose is due (three-four weeks) which is why it makes sense while the vaccines are in short supply to get those first doses into as many arms as possible:
Polack et al. (Dec. 31)1 report a vaccine efficacy of 94.8% against Covid-19 after two doses of the messenger RNA (mRNA) vaccine BNT162b2 (Pfizer–BioNTech). The authors also report a vaccine efficacy of 52.4% from after the first dose to before the second dose, but in their calculation, they included data that were collected during the first 2 weeks after the first dose, when immunity would have still been mounting.1 We used documents submitted to the Food and Drug Administration2 to derive the vaccine efficacy beginning from 2 weeks after the first dose to before the second dose (Table 1). Even before the second dose, BNT162b2 was highly efficacious, with a vaccine efficacy of 92.6%, a finding similar to the first-dose efficacy of 92.1% reported for the mRNA-1273 vaccine (Moderna).3