Are people who received a COVID-19 vaccine 'walking biological time bombs'?
Contrary to what a video post claims, early studies suggest that the current COVID-19 vaccines provide at least some protection against new virus variants. The video's argument assumes that vaccinations will result in more dangerous and deadly variants. There's no publicly available evidence that's true, and there's a good bit of evidence it's not, since variants arise in populations of un-vaccinated virus-susceptible people.
Viruses change over time -- with or without a vaccine -- that's normal.
A February 2020 article in Nature Microbiology on virus evolution argued that "predicting how virulence might evolve is an extremely difficult and perhaps futile task," and warned against "rampant speculation."
The CDC strongly recommends people get vaccinated, which it says is an "essential tool to protect people against COVID-19, including against new variants."