Interestingly (perhaps), I had Covid over Christmas and then a hospital appointment for CML in the New Year. N protein antibodies were not detected, apparently, which really surprised me! Plenty of S ones. Anyway, I have just had dose 4/booster. I agree with others that we need to reach a point where the virus is considered endemic, as has just happened in Denmark. That has to be the end point. Unfortunately, not everywhere thinks this way (yet), in particular in Asia. I'm due to travel there next month so having my additional dose/booster was ultimately a decision based on maximising my chances of not testing positive by PCR (we have to test three times: once 72 hours before leaving the UK, once on arrival and once on day 4 or 5). I have no doubt that should I come across COVID again, it will be mild, as it was over Christmas, but that won't necessarily stop me testing positive and with Omicron and its relations, there's so much about and it's so infectious, I want to take what steps I can to minimise the chances.
On the science and views pro and against further boosters, as a scientist (and lawyer) myself I'm very wary of single articles or videos that may fit our own/one point of view and feed confirmation bias. One needs a more balanced review, then decide which opinion has the strongest basis. The short answer is nobody knows yet, for this virus, these vaccines and how many doses may be problematic and when. We need research and balance. I'm also I'm afraid not a complete fan of Dr Campbell - a lot of what he does is good and useful information, but he gets things wrong where he is going beyond his own expertise. There's a video from an expert online which critiques Dr Campbell's own video on Ivermectin vs Pfizer antiviral, and the critique is pretty strong albeit delivered with tact and care by a real expert in that particular field. So I do watch his stuff, I just don't necessarily take it at face value and check if there are contrary views or more detailed explanations...