ACTUAL vaccines go through periods of proper testing.
The Covid vaccines are FDA approved. That means that they went through all three phases of clinical trials, as well as the "fourth" phase, which is post-approval monitoring.
In this single clinical trial About Our Landmark Trial, 46,331 participants volunteered and were enrolled. That's just one clinical trial out of many. By federal law, each formulation of a drug must be tested in the population for which it is intended. That translates to several clinical trials being run for each vaccine formulation--and with tens of thousands of participants for each trial, I do not know how anyone can say with a straight face that the vaccines are untested.
FYI, the narrative that the vaccines are experimental was devised long before Covid was even a blip on the horizon. Professional antivaxxers have used that language for DECADES.
If you want to find out about actual vaccine testing from a real source, try https://www.clinicaltrials.gov/. This is a searchable database used by scientists all over the world to register clinical trials. All you have to do is put "covid" in the "Condition/disease" field and "vaccine" in the "Intervention/treatment" field, and you can find all of the registered Covid vaccine trials.
Another scientific source is www.pubmed.gov. This is also a searchable database, which contains references to medical/scientific articles, along with abstracts (summaries), usually a link to the article, and sometimes the full text of the article.
If you learn how to use the databases that scientists use, then you can actually fact-check those professional antivaxxer claims and see just how much they are lying to you.
BTW, do you think that all of those tens of thousands of vaccines I mentioned before, the ones designed only to produce antibodies for research use, are FDA approved? The only testing those vaccines get is 1) does it kill the animal? And 2), does the animal receiving it produce the antibodies we want? The answer to the first should be "No," and the answer to the second should be "Yes." If either answer is different, then it's back to the drawing board to design another vaccine.