I talked to an AT&T phone rep who has been working from home since March 2020. AT&T requires all such workers who work exclusively at home (and are never in the office) to be fully vaccinated.
If you are an AT&T phone rep who has been working from home since the start of the pandemic, AT&T requires you to be fully vaccinated to continue your employment (religious or medical exemptions are available).
Also, the union sided with the company in requiring vaccination for employees who work 100% at home.
The only possible explanation for such a requirement is that AT&T believes that the virus can be transmitted over the phone lines.
I would love to see that data on that one.