If you just say unvaxxed, then people will ask about "partially vaxxed". If you put "partially vaxxed" in a column of its own and it shows even the slightest protection, you get people thinking that they can just get the first dose. If you put "partially vaxxed" in a column of its own and its show no protection similar to being unvaxxed, you get people saying, "see, the vaccine doesn't work".
No vaccination and "partially vaccinated" are really the same, because immunity isn't achieved with only the first dose. Therefore, they should be together.