Updated

Researchers at Pompeu Fabra University reported on November 13, 2026, that mice recovering from acute viral infections had lasting spleen changes and weakened immune responses. The study, published in Cell Death & Disease and led by Andreas Meyerhans, an ICREA research professor, found that the infection caused the spleen to develop fibrosis, a buildup of scar-like tissue, and disrupted how immune cells were arranged. These changes interfered with the interactions needed to activate T cells, the specialized cells that help recognize and destroy infected cells, so the mice stayed less able to mount effective responses to new challenges even after the virus was cleared. Meyerhans said the common view that acute viral infections are minor and transient may underestimate consequences that are not immediately visible. The researchers found that prior vaccination completely prevented these harmful changes in the mouse model. Vaccinated mice kept normal spleen structure, and their T cells worked at levels comparable to mice that had never been infected. The findings have not been tested in people, and ScienceDaily noted that the work raises questions about how infections affect long-term immune health. The researchers stressed the value of scientific evidence amid political influence on vaccination policy, and ScienceDaily reported that the findings could shape how officials explain the value of vaccines to the public.