That is of course not true. Like every vaccine or practically any injection, the proteins and other substances are toxic in quantity. The key is that the quantity is very low, less than 100 pg/ml See https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciab465/6279075
TIny amount of toxins are not toxic. That is the essential mechanism of homeopathic medicine as well as most vaccines, The caveat is that the gene therapy (J&J) to produce the spike proteins is still experimental although it has over 20 years of history for immunotherapy for cancer treatment. The mRNA in Moderna and Pfizer is a more direct method of producing the proteins, it's newer and less tested, but a little simpler. Getting the toxin dose right might be a little harder with mRNA since it is unstable and it's difficult to tell how much anyone gets.
Suffice to say I would have no problem with a tiny (100 pg/ml) amount of arsenic because I know that won't be harmful. I can't see a reason to purposefully take arsenic. Do you peel your potatoes or eat the skin? If you eat the skin you are probably eating tiny amounts of arsenic.
And if the arsenic don't get you...the carbohydrates will.