Uncle.....Imuho this term is a conman statement. This means those who got vaccinated or having previous infections can become immune to the disease but it doesn't mean the virus will not cling on their body to infect individuals who lack immunity.
Depends how the virus is transmitted lah.
Virus on clothes and body that one is called spread by fomites.
Not all virus is spread like that.
Initially it waw thought that covid was spread via fomites but lately seems to be less considered spread that way.
There is a growing body saying it is aerosol or even airbone.