Contrary to initial assurances, the spike protein can be produced for months. From Igor Chudov at igor-chudov.substack.com:
COVID Vaccine is a GIFT THAT KEEPS ON GIVING
Remember how we were told that “the vaccine stays in the arm” and that “harmless spike protein is only produced for a couple of days.” They said they were sure of that, despite no data to confirm their statements.
Well, sadly, it turns out that they lied to us. The data is now in, and it proves such claims wrong!
A clever scientific study by Brogna et al., just published, detected the presence of spike protein in COVID-vaccinated people six MONTHS after vaccination – and excluded the possibility of cross-contamination of experimental data with wild-circulating COVID infections.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/prca.202300048
What the Scientists Did
The study’s authors used a sensitive test, called mass-spectrometry to detect a specific amino-acid sequence that exists only in the vaccine-induced spike protein.
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