This is incorrect with several unproven virology theories blended together. Immune systems are oriented to barriers between internal & external.. most of what is classified as viral illness is introduced at eyes, nose & mouth with T-cell response initially later B-cells may add backup defenses. Injecting mRNA is an old lab tool known as TRANSFECTION it's also how all virology is done with CRISPR sequences transfected into cell culture replicated by E.coli or other bacteria then stuffed into rodents to model disease & design vaccines.. it's also known as Gain of Function which is pure clones not a triumph of virology over nature. https://web.archive.org/web/20161206155142/http://www.gryphonscientific.com/wp-content/uploads/2016/04/Risk-and-Benefit-Analysis-of-Gain-of-Function-Research-Final-Report.pdf

Transfection of ANY and ALL non-self proteins triggers immune systems to destroy the non-self proteins and it made headlines in 1999 when promise of genetic modification to cure disease was shown to be total failure w Biotech Death of Jesse Gelsinger.. turns out even the most benevolent aim can't fool Mother Nature. Spike is irrelevant the body ALWAYS destroys non-self proteins.
https://web.archive.org/web/20080517050534/http://www.nytimes.com/library/magazine/home/19991128mag-stolberg.html

@shortstories Germ Theoretical presuppositions have some scientific merit; but Medicine in the United States peaked in the 1930s, followed by a precipitous decline which was overshadowed by the War, and largely forgotten in the conformist ‘50s wherein allopathic doctors enjoyed prestige-of-position comparable to Priesthood in the Roman Catholic West during its heyday.

This status lasted more or less intact in many areas of the US up through the 1980s. For reasons not entirely clear to me, though, I definitely recall a sea-change throughout the 90s (may have been a side-effect of feminism; not entirely certain). But in any case, the more than a century-old hard fought public trust in the medical establishment utterly and rapidly imploded with the Scamdemic.