Confusion

"Double jabbed people are catching Covid and passing it on to those they live with, warn experts who have studied UK household cases.
Even if they have no or few symptoms, the chance of them transmitting the virus to other unvaccinated housemates is about two in five, or 38%.
This drops to one in four, or 25%, if housemates are also fully vaccinated."
BBC
Provided that being or not being vaccinated severely affects all areas of life and free movement nowadays, please explain that report to me. Because to my understanding that means I am neither a protected one nor a protector.
Vaccine (noun) : "a substance used to stimulate the production of antibodies and provide immunity against one or several diseases, prepared from the causative agent of a disease, its products, or a synthetic substitute, treated to act as an antigen without inducing the disease."