Is it absolutely necessary to wear masks after full vaccination?

This question really bothers me. My wife and I will complete our vaccinations today, so the question is rather immediate for us.

The current thinking seems to be that even though a person is protected by antibodies in most parts of the body, not enough can be mobilized to the nose and throat in time to prevent virus multiplication.

For instance, “The trials have so far analyzed only blood, but testing for antibodies in mucosa would confirm that the antibodies can travel to the nose and mouth. Tal’s team is planning to analyze matched blood and saliva samples from volunteers in the Johnson & Johnson trial to see how the two antibody levels compare.” This is from https://www.baltimoresun.com/coronavirus/ct-nw-nyt-coronavirus-vaccine-face-masks-20201208-7cjld4vxivew3jhjgjs7dgdg3a-story.html

It appears that the recommendation to wear masks after vaccination is based, like many COVID-related recommendations, on an assumption rather than science. We know that the virus can travel from the mucosa to the rest of the body. But we assume that antibodies cannot travel in the reverse direction.

To me, personally, the biggest payoff of the vaccines is a return to near-normal. We may get answers piecemeal, depending on which vaccine was administered.

I would welcome scientific responses to this question.