Pompeu Fabra researchers report vaccination prevented lasting spleen damage and immune impairment in mice after viral infection

Scientists at Pompeu Fabra University in Barcelona reported in Cell Death & Disease that mice recovering from an acute viral infection developed lasting immune impairment even after the virus was controlled. The team found that infection caused fibrosis, or scar-like tissue, in the spleen and disrupted the normal positioning of immune cells, weakening interactions needed to activate T cells. Mice vaccinated before infection did not develop the spleen damage or the immune dysfunction, according to the study.

The evidence came from examining mice after acute infection had been cleared. Researchers reported persistent fibrosis and altered immune-cell architecture in the spleen, interfering with interactions needed to activate T cells, which are central to adaptive immunity. First author Paula Cebollada Rica said animals remained immunocompromised after the virus was no longer detectable. The study used vaccinated and unvaccinated mice, but sample size was not stated in the source, and the findings are limited to an animal model.

The findings challenge the common assumption that an acute viral infection ends once symptoms resolve and the virus is controlled. They add a structural mechanism to growing evidence that infections can leave lasting immune traces: scar tissue in a lymphoid organ can impair future immune responses. The vaccination comparison is notable because it suggests that preventing infection in the first place may also prevent organ-level damage, not merely reduce symptoms.

The result matters because it reframes vaccination as potentially protecting immune-system integrity, not only preventing illness. The finding is relevant to public-health decisions about preventing viral diseases, especially for people whose immune systems are already vulnerable. It also links vaccine benefit to organ-level protection: by preventing infection, vaccination may preserve the spleen's structure and the cell interactions needed for later immune responses. The immediate evidence is from mice, so human studies are needed to confirm spleen scarring and immune impairment.