I am a molecular biologist, and it kinda works this way. B cells are called memory cells because they hold onto that “memory” of the invader for a really long time. You probably haven’t had an MMR or a Tetanus vaccine in 10+ years because the body is really good at remembering. But we have to get flu boosters every year because the flu mutates so rapidly that traditional b cells won’t recognize the flu after a year of mutating. (RNA viruses can’t correct their mutations so they change much faster than bacteria or DNA viruses). RNAi was still pretty new when I was in school and I haven’t kept up with the research so I can’t speak to it’s effectiveness at long term immunity.
Given the position of this statement in the article, I’m guessing they are trying to imply a correlation in rate of aging. Like 1 dog year = 7 human years. They are further implying that if a mouse maintains immunity for 90 days, a human would maintain immunity for 10 years.
It should be clear that it is the reporter stating this, not the original authors of the study.
And you are absolutely right to be skeptical about that, that is a crazy level of extrapolation.