This claim is mostly overblown at this point. It was a legitimate concern early on, but it hasn't been true for some time.
The vaccine claims are also misleading. Herd immunity by vaccination is not the only way to protect society, and the distinct lack of discussion or recognition of immunity from infection is conspicuous. COVID's infection fatality rate for certain cohorts is low enough that vaccination isn't strictly needed, and arguably taking a different tack on this could potentially have saved far more lives.
For instance, consider if we had only isolated and vaccinated those at greatest risk of death and complications from COVID (40 and older, immunocompromised, comorbidities), and then shipped the remaining vaccine supply to the third world to suppress the emergence of variants. We might not have had Delta or Omicron at all. It's not at all clear that this would not have saved more people in the long run.
Beating this vaccine mandate drum is blinding people to other rational solutions. It's not going to end well. This convoy is probably only the beginning.