About the Authors

Juan Picazo

jpicazo@picazo.net

Affiliation Medicine Department, School of Medicine, Universidad Complutense, Madrid, Spain

Jesús Ruiz-Contreras

Affiliations Pediatric Department, Hospital Universitario 12 de Octubre, Madrid, Spain, Pediatric Department, School of Medicine, Universidad Complutense, Madrid, Spain

Juan Casado-Flores

Affiliations Pediatric ICU, Hospital Universitario Infantil Niño Jesús, Madrid, Spain, Pediatric Department, School of Medicine, Universidad Autónoma, Madrid, Spain

Sagrario Negreira

Affiliations Pediatric Department, Hospital Universitario 12 de Octubre, Madrid, Spain, Pediatric Department, School of Medicine, Universidad Complutense, Madrid, Spain

Fernando Baquero

Affiliations Pediatric Department, School of Medicine, Universidad Autónoma, Madrid, Spain, Pediatric Department, Hospital Universitario La Paz, Madrid, Spain

Teresa Hernández-Sampelayo

Affiliations Pediatric Department, School of Medicine, Universidad Complutense, Madrid, Spain, Pediatric Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain and CIBER of Respiratory Diseases, CIBERES, Madrid, Spain

Enrique Otheo

Affiliation Pediatric Department, Hospital Universitario Ramón y Cajal, Madrid, Spain

Cristina Méndez

Affiliation Medical Department, Pfizer SLU, Madrid, Spain

On behalf of Heracles Study Group

Membership of the Heracles Study Group is provided in the Acknowledgements

Competing Interests

J.P. reports grants and non-financial support from Pfizer S.L.U., Madrid, Spain during the conduct of the study, grants and non-financial support from Pfizer S.L.U., Madrid, Spain, and grants from GSK, Madrid, Spain, outside the submitted work. J.R-C. reports personal fees from Pfizer S.L.U., Madrid, Spain, during the conduct of the study, and grants from Pfizer S.L.U., Madrid, Spain, outside the submitted work. J.C-F., S.N., E.O. and T.H-S. report grants from Pfizer S.L.U., Madrid, Spain during the conduct of the study. F.B. has nothing to disclose C.M. reports grants from Pfizer S.L.U., Madrid, Spain, during the conduct of the study; and is an employee of Pfizer S.L.U., Madrid, Spain. This does not alter our adherence to PLOS ONE policies on sharing data and materials if there is a previous authorization by the corresponding hospital(s).

Author Contributions

Conceptualization: JP JR-C CM. Data curation: CM. Formal analysis: JP JR-C CM. Funding acquisition: CM. Investigation: JP JR-C JC-F SN FB TH-S EO CM. Methodology: JP JR-C CM. Project administration: JP JR-C CM. Resources: CM. Software: CM. Supervision: JP JR-C CM. Validation: JP JR-C CM. Visualization: JP JR-C CM. Writing – original draft: JP JR-C JC-F SN FB TH-S EO CM. Writing – review & editing: JP JR-C JC-F SN FB TH-S EO CM.