We prospectively enrolled (1983-1985) in a randomized trial of R vs. P previously healthy, premature (prem), or CHILD with chronic pulmonary disease. We followed them over 7 yrs for: respiratory illness, wheezing (W)/reactive airway disease (RAD), and pneumonia (PN). Between yrs 5-7 we did PFT's and at≥ 7 yrs, methacholine challenge (MC) if FEV1 ≥ 70% of predicted value. One pulmonologist (blinded) scored and interpreted PFTs. We treated 42 pts aged 1-33 months; 2 died (1R and 1P) and 5P were lost to FU; 35 (23R and 12P completed 212 visits. 4 were prem (3R and 1P), 3 of these had BPD (2R and 1P). RSV reinfection occurred in 2R and 1P (NO REHOSP). Two pts. were rehospitalized (1R and 1P). Members of 24 households smoked (17R and 7P). From yr 1-3, there were more RAD/W/PN in P than R (mean score 22.3/12P vs. 15.8/23R, Kruskal-Wallis test, p=.069); for all yrs it was 22/12 vs. 15.9/22R, p=0.95. After informed consent, 19 subjects completed PFTs (13R, 6P), PFT's were scored (norm/mild vs. mod/sev); 7/13R 53% had norm/mild PFT vs. 0/6P, Fisher's exact T test p=.043. On MC challenge, (7R and 5P), there was more react in P vs. R p=.036. Scoring done weighing for severity for 19 pts. (13R and 6P), showed a significant difference in favor of previously treated R pts. p=.0243. There were trends in favor of R for FVC% (mean 87.6 vs. 80), FEV1% (87.6 vs. 79.2), and FEF25-75% (97.1 vs. 81.4) but no statistical significance (t test p=.3,.16 and.3 respectively). No untoward effects were identified from R exposure. Weighed severity scores suggest long term beneficial effect of R however, larger numbers should be evaluated.(funded by ICN Pharm)