Advanced NICU care has improved survival of very premature infants, but their improved survival is accompanied by long-term complications such as impaired lung function. Infants born prematurely are highly susceptible to recurrent, severe respiratory viruses, suggesting a state of immune deficiency, specifically T cell immunity. They also suffer from diseases characterized by chronic inflammation associated with T cell activation, including bronchopulmonary dysplasia. This clinical paradox (T cells able to activate but not protect) is not well explained.
