[moocow01]

It hasn’t been studied yet but it’s very unlikely this is true.

Is there any previous vaccine that this has ever been true of? If it was wouldn’t that enable the disease to continue to be rampant among groups who were not vaccinated?

[Andys]

A quick google shows it is starting to be studied now. We just don't know yet, and its not a sure thing. It may take a future generation of vaccine to be more effective at preventing transmission.

> The science behind this seeming contradiction is relatively straightforward. Vaccines like Pfizer’s and Moderna’s are injected into deep muscle and provide so-called systemic immunity. But they may still leave areas, particularly nasal mucous passages, where the virus is relatively free to multiply. Even without making the host sick, that virus can then potentially spread through coughing or sneezing, just as it is spread by a person with a full-blown coronavirus infection.