Is Moderna Better Than Pfizer–Or Is It Just a Higher Dose?

> A recent (but not yet peer-reviewed) study of more than half a million U.S. veterans showed that the Johnson & Johnson shot’s protection against infection (whether or not that leads to disease or hospitalization) had plummeted from 88 percent to 3 percent by mid-August, while the other vaccines’ effectiveness had declined much less

Ex https://www.medrxiv.org/content/10.1101/2021.10.13.21264966v...

...Though

> Paul Offit, who directs the Vaccine Education Center at the Children’s Hospital of Philadelphia, said that J&J may turn out to be “every bit as good as the mRNA vaccines” when compared two doses to two doses. He also suspects that a single dose of J&J would prevent more hospitalizations and deaths than a single dose of Pfizer or Moderna [should not we have data about this latter statement?] [...] thanks to the way it tickles [...] T cells, which help prevent infections from progressing into severe disease. [...] [B]ut some studies have shown that the mRNA vaccines produce T-cell responses with at least as much vigor as J&J’s. [John Moore, microbiology and immunology professor at Weill Cornell Medicine] says that antibodies are a better proxy for protection anyway, and the Moderna and Pfizer options consistently produce more of them in the vaccinated

Other times, we look at a number that correlates: what is the increase in _antibody levels_? One example from this article:

> A recent (but not yet peer-reviewed) study of more than half a million U.S. veterans showed that the Johnson & Johnson shot’s protection against infection (whether or not that leads to disease or hospitalization) had plummeted from 88 percent to 3 percent by mid-August, while the other vaccines’ effectiveness had declined much less. Research published in the past few months also signals that Moderna’s shot beats out Pfizer’s in terms of both antibody count and hospitalizations prevented, while a National Institutes of Health study released earlier this month found that Moderna’s booster shot lifted participants’ antibody levels a bit more than Pfizer’s, and that both mRNA boosters were miles ahead of J&J’s.

My understanding is that we don't know how much antibody levels need to increase to provide a level of safety. Or, for that matter, if at some point, further antibody levels don't help at all! If there's a light rain, a full-body drysuit will keep you dry. But so will an umbrella! The drysuit is overkill!

We certainly want antibodies against the virus, but I don't believe we know how much is overkill. One reason this might matter is if we could have given smaller shots to people and ramped up injections much sooner. Or even in the present, we could send more injections to other countries for lower cost, if a certain volume of vaccine could be given to more people.