Pandemic influenza A (H1N1) virus 2009 in a prospectively followed cohort of prematurely born infants.

The hospitalization rate for pandemic influenza A (H1N1)v 2009 of 150 prospectively followed, prematurely born infants did not differ significantly from that of term-born infants from the same geographical area (0.7% vs. 0.07%, P = 0.12), but was higher for other viral lower respiratory tract infections (5.3% vs. 0.6%, P < 0.0001). Pandemic influenza A H1N1 immunization uptake in the prematurely born infants was low (9.3%).