IF this vaccine works then those who are vaccinated should not care if some choose not to get vaccinated.  If this vaccine does not work then why mandate it?  If an unvaccinated person can give the sickness to a vaccinated person then clearly the unvaccinated person would also have still caught the illness and spread it even if they had been vaccinated as well.  IF those who are not vaccinated get sick they will then have immunity via the virus itself.