Neutrophils clear viruses, but excessive neutrophil responses induce tissue injury and
worsen disease. Aging increases mortality to influenza infection; however, whether this is
due to impaired viral clearance or a pathological host immune response is unknown. Here
we show that aged mice have higher levels of lung neutrophils than younger mice after
influenza viral infection. Depleting neutrophils after, but not before, infection substantially
improves the survival of aged mice without altering viral clearance. Aged alveolar epithelial …