This is a very interesting article and as long as the substances are very pure, it's probably low risk of any real health danger. However, I would really want to be very sure about that point before putting anything into my nasal passages.
As a scientist working in the pharmaceutical industry for many decades, I can say there are several big issues with this vaccine method. First, you will never know if it really works until you run blinded clinical trials against a placebo. This is the only way to tell and that is why it's required for any new drug/vaccine to be launched on the market. You can't just take a antibody test and see if it works. Even if there were the right antibody tests for these peptides, it might indicate some activity, but without using rigorous scientific method, there could be many other factors why you could see a response. Like you were exposed already to the virus and didn't know it.
Second immune response to peptides is significantly less effective generally. Whole viral proteins in the marketed vaccines are the best method to create an immune response. That is why almost all vaccines use some whole enzyme method or multiple proteins.
Finally the real problem with this method is that peptides are extremely unstable and very difficult to delivery into the body. That is why the most vaccines have to be injected, the oral and nasal dosage forms are specialized formulations.
Peptide memetics is a large field of study at both academic and pharmaceutical company labs and has been going on for many decades. Using peptides as drugs shows a huge amount of promise since is mimics the natural biological processes and are inherently effective, safe and non-toxic.
The problem has always been that it's extremely difficult to deliver peptides into the body. The bodies chemistry has a very large number of pathways to break down peptides and proteins. It is basic to biologic chemistry since almost all biologic processes are done by enzymes and peptides, and the body needs ways to break these down when they are finished their job. This delivery issue is why most peptide drugs today are in an injectable dosage form. It's the only good way to get them into the blood steam and have them circulating through the body. They still quickly breakdown especially after entering the cells, but usually last long enough to have their intended affect. I can tell you that there have been a very large number of peptide drugs that have shown real promise, but this stability issue has limited their application and the reason that there are still so few on the market even after decades of research. We have developed tricks in the industry, the main one being to change the peptide structure to make them more stable and those can work, but then the activity can be substantially lower. It is a very difficult problem that continues to be studied.
Today there are several nasal dosage forms of peptide drugs on the market, however these usually have very specialized formulations, that include stabilizers, special particle size ranges and shapes that enhance absorption or even nanoparticles. However as noted above, the first cells they see in the nasal passage will start to digest them quickly. I doubt very much if any of the peptide formulated up in your kitchen will actually make it into the blood stream where it could then effect the immunity.
I won't say don't try it, but there are always a serious risks and most likely your just wasting time and money. Hey, it's surely better then injecting bleach!
I'd be happy to discuss with anyone if they would like more information.
As you can tell, I'm have more of a mainstream approach to health issues. You are totally correct that delays and avoidance of risk in the development process of the pharma industry and with the government clauses personal suffering every day. And let's not even start about the the pharmaceutical industry's need for "commercial success" before they even start working on a disease or problem.
However, I think you may have missed my main premise, the fact that degradation is a huge hurtle in any peptide application, it is a clear fact that peptides are digested extremely quickly and therefore are very ineffective as any type of drug. You are correct that the antibody test presented could at least show if these peptides actually enter the body and if you are getting an immune response to these specific peptides. I would be very interested to hear if anyone has tried it on themselves and gotten positive results. However, the other problem here is that even if your body does develop a immune response to peptides of the virus, it does not necessarily correlate to having a immune response to the virus itself.
I can see a pathway for this method to develop immunity to the virus itself, where the virus enzymes are broken down to the peptides you have taken and have a general immunity response offering some protection. However as a scientist personally I would need to see proof before trying this method. That would start with some lab trials showing these antibodies have and affect. Then of course we are back to clinical trials which are really the only way to prove this method work. And as you note this takes a lot of time while people are suffering and dying.
So my final point is sure, you can try this method while you are waiting for the vaccine, but it definitely shouldn't be a replacement for the vaccine. Also you should keep in mind there are still some risks of something untested and mixed up in your kitchen, but hey, I'm not stopping anyone.
Finally if you really want to protect yourself from the virus until you can get the vaccine, then I suggest you follow the swiss cheese advise.
https://my.clevelandclinic.org/-/scassets/files/org/employer-solutions/covid-19-workplace-safety-faqs.ashx
The best way to have some level of protection is to follow the recommendations of the epidemiologists and be extremely careful about your behavior. I know a lot of people can't do this due to work and personal reasons, but honestly if everyone were just more careful about how they act in this situation, we all would be better off.
Stay safe out there!