Chris,
I understand, and respect, what you're saying about the J&J vaccine possibly being better against the new variants which have appeared in the U.S., but I tend to disagree somewhat since, at this point, there really is no hard data comparing all 3 producers equally on the question of which is superior with the currently known variants that have appeared to originate in the U.K, South Africa, and Brazil..
There are a number of reasons for me saying that but, to me, the most significant factor lies with the timing of the crucial Pfase-3 trials relative to the appearance of the variants in the U.S. Both Pfizer and Moderna ran their Phase-3 trials for a 4 month period from late July, 2020 to late November, 2020. The 4 month Phase-3 trials for J&J from late September, 2020 to late January, 2021.
The U.K. variant first emerged in early October, 2020 and was first detected in the U.S. in late December, 2020,. The South African variant also first emerged in early October, 2020 and was first detected in the U.S. in late January, 2021. The Brazilian variant first emerged in early January, 2021 and was first detected in the U.S. in late January, 2021. In short, making direct comparisons is a bit like comparing apples and oranges. The Pfizer and Moderna' vaccines were tested before the emergence of the new variants, and the J&J vaccine was was still being tested when the variants began making the rounds. Also, the focus of the J&J testing pertaining to the variants, compared to the total population of their overall test base, was very limited.
So, I'll say again, take whatever vaccine is offered as soon as it's available to you and don't concern yourself too much about which one is best. It's a whole new world we're in now in now and far too early in the game to second guess things.