The Puerto Rican Infant Metagenomic and Epidemiologic Study of Respiratory Outcomes (PRIMERO): Design and Baseline Characteristics for a Birth Cohort Study of Early-life Viral Respiratory Illnesses and Airway Dysfunction in Puerto Rican Children

Epidemiologic studies demonstrate an association between early-life respiratory illnesses (RIs) and the development of childhood asthma. However, it remains uncertain whether these children are predisposed to both conditions or if early-life RIs induce alterations in airway function, immune responses, or other human biology that contribute to the development of asthma. Puerto Rican children experience a disproportionate burden of early-life RIs and asthma, making them an important population for investigating this complex interplay. PRIMERO, the Puerto Rican Infant Metagenomics and Epidemiologic Study of Respiratory Outcomes, recruited pregnant women and their newborns to investigate how the airways develop in early life among infants exposed to different viral RIs, and will thus provide a critical understanding of childhood asthma development. As the first asthma birth cohort in Puerto Rico, PRIMERO will prospectively follow 2,100 term healthy infants. Collected samples include post-term maternal peripheral blood, infant cord blood, the child's peripheral blood at the year two visit, and the child's nasal airway epithelium, collected using minimally invasive nasal swabs, at birth, during RIs over the first two years of life, and at annual healthy visits until age five. Herein, we describe the study's design, population, recruitment strategy, study visits and procedures, and primary outcomes. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported in part by the Sandler Family Foundation; the American Asthma Foundation; the RWJF Amos Medical Faculty Development Program; Harry Wm. and Diana V. Hind Distinguished Professor in Pharmaceutical Sciences II; the American Lung Association [CAALA2023]; Wohlberg and Lambert Endowed Chair of Pharmacogenomics (MAS); the National Institutes of Health, National Heart, Lung, and Blood Institute [5U01HL138626 and 1K23HL169911]. The content of this publication is solely the responsibility of the authors and does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. government. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Protocols and documents were approved by the University of California, San Francisco Institutional Review Board (IRB# 10-00085) and a National Institutes of Health-appointed Observational Study Monitoring Board (OSMB), ensuring data safety, study progress, and confidentiality protocols. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Access to data and samples generated within the PRIMERO study is governed by a set of guidelines aimed at fostering collaboration and ensuring the integrity of the research endeavor. Data access is evaluated on a case-by-case basis and is limited to PRIMERO-approved investigators. Approval as a PRIMERO investigator involves evaluation by all three Principal Investigators (PIs; Drs. Sheppard, Seibold, and Rodriguez Santana) and recognition by the National Heart, Lung, and Blood Institute (NHLBI). External investigators interested in contributing to the mission, infrastructure, and sustainability of PRIMERO are encouraged to apply for investigator status.