I just clicked through that video but it looked like he was just going off the levels of circulating antibodies induced after each booster. The problem with that approach is there is no correlate of protection for antibody levels so higher doesn't necessarily mean better. Add to that the fact that circulating antibody levels will always decrease after the initial e following vaccination and I don't think it means a lot. What we really need are studies on the diversity of antibodies generated, memory B cell formation, and memory T cell formation following the booster doses. We'll get them eventually, but that work takes time and $$$$.