This is the key problem. "Credibility of the author" should mean nothing, data should be analyzed in its own right entirely irrespective of who it's from. Who happened to run a study, on its own, means absolutely nothing. Dramatic bias is identifiable by cross-referencing opposed studies and comparing their methodologies.
Also, we can note the lack of credibility amongst those publicizing and pointing-to 'the science' over the last two years because of reality not performing to their predictions.
That may not be the fault of the science being faulty, but potentially the scaling impacts and whatnot that affect transition from laboratory environment to reality. But regardless of the cause, credibility of health institutions and their spokespeople is at AND DESERVES TO BE AT ridiculous lows because of the rampant false statements, predictions, and ideas they have produced.
And that can be added atop what should be preexisting incredulousness of drug companies based on prior activities by those drug companies and those companies self-interested stake in selling their shit.
Or, put another way, prinCZess still remembers when this shit was 'two weeks to slow the spread' and 'get the J&J vaccine, it's one and done!' instead of a perpetual, unending bullshittery of power-grabbing by malicious partisan parties and 'Oh, our product isn't as effective as we lied to you about, so you might have to get three...maybe four...or five...or just a regular booster to keep you current'.