At the moment it's one size fits all.
I think this is the main, if not the only issue, with regards to vaccination risks. Diversification in general is underutilized in modern medicine. Precision medicine has become negativity connotated.
Some clinicians have found it helpful to divide the dose into two to four mini doses, with each dose given a full month apart to ensure there are no delayed reactions.
The issue with the vaccine trials is that they aren't smart trials. Smart trials would try all different kinds of approaches and determine the best scenario for different subgroups and patient groups. They would identify how to determine the correct dose and regimen for immune compromised, for B cell depleted, for example.
Why aren't they doing it despite the huge available funding? Because the current system discourages it. There's still this idea in medical leadership that large multi-centered RCTs are the way to go and that everything else is to be ignored because it's not good enough. But statistically speaking, this isn't correct.
You don't develop drugs for the most average person that can exist. Typical RCTs methodologies try to establish consensus for exactly this person, the average Joe, but not for patients with multiple comorbidities, untypical patients. They are still included, of course, if possible, but not in a statistically significant representation. Smart trials can fix such shortcomings.
That's why it can only be speculation if mini-doses still provide the same efficacy and for which vaccine and how it affects safety. I think their initial hope was that one-dose for all would be an option, to reduce the load at vaccination stations.
This also opens the question why we don't just try to push the antibodies up to nowhere. As with every drug, there have to be reasons why they can't just quadruple a single dose. These things are usually tested on animals and there's always a limit. But companies don't have to publish negative attempts. So if they tested it with toxic doses, you won't find it. If they tested other things that turned out ineffective, it remains their competitive asset. So that other companies can waste funds on the same approach as well.
But it's safe to say that we need antibodies at least for herd immunity. So why don't we monitor people for antibodies and determine this way, if they need another shot? If mini-doses don't work with regards to antibody concentrations, why not try something else? Because medical leadership hasn't approved any other regimens.
The other issue, and I'm really concerned by this, is the new trend to issue vaccination passes. In Germany, you have to take the official regimen and not all vaccine manufacturers are accepted. Sputnik, for instance, isn't accepted, and you won't get a vaccination pass for it. Not like we need it with ME, but who knows how long this system will last and how restricted access really becomes with such an indirect vaccination mandate? So if I'd like to go with Novavax and decide if and when I need another shot based on my antibodies, this isn't accepted. I have to take the second shot at the right point of time. If I miss it, I have to start all over again. It's stupid to think that you should take another first dose only because you waited one more week. It might even be a risk because the trials don't reflect how full vaccination affects an already vaccinated population.
What I'm also considering is that I'd ask my doctor to split up the dose, half the dose in both arms. One of the risk vectors, after all, was the spreading of spike proteins from the muscle tissue into other areas and organs where they aren't supposed to go, but predominantly the blood. Lower concentrations might reduce the overall risk to spread, while it's fair to say that two arms also increases the risk on a binomial scale. But I'd assume that half the dose decreases the risk more by more than half per arm.
I'm not surprised that they eventually approved the Biontech vaccine, but without addressing the lost efficacy and without addressing the leaking spike proteins, the interactions of the proteins that can cause thrombocytopenia and thrombotic events, without addressing the relatively frequent anaphylaxis, and barely recognizing the myocarditis risk for children, as if there weren't approaches how to vaccinate children while addressing the risks, either by dose adjusting, or by using other vaccines. They try to sell every "one for all" approval like it's without alternatives. But there are alternatives.
They want to make decisions for us, but not with us. They look at average people like they are too stupid to take responsibility anyways. It's like drunk drivers. If you don't prevent cars from driving drunk drivers, they are all over the place, right? People have no level of moral thinking or self control to take responsibility for themselves and for other drivers. If they think that, I guess they live in another reality. Even drunk, most people know themselves and they don't drive drunk. They don't swallow pool cleaner because a random person told them so. They know how to check facts. There are some black sheep, but that's no reason to restrict the freedom and personal rights of every person.
In fact, this indoctrination system makes the blind trust phenomenon only worse. If critical thinking is less and less utilized, people might just lose it. So how are they supposed to navigate one day, when deep fakes can persuade anyone that it's authentic? If you don't know who to trust, and you don't know how to verify the integrity of claims, what are you supposed to do? People will just randomly do anything, believe the first entity that "makes sense". And everything "makes sense" that sounds simple and populistic.