JMIR Publications

ABSTRACT

Background:

Acute gastroenteritis (AGE) and acute respiratory infections (ARI) cause significant pediatric morbidity and mortality. Developing childhood vaccines for norovirus and respiratory syncytial virus (RSV) and optimizing current vaccines for rotavirus and influenza should be guided by birth cohort data that defines the natural history of infection and acquired immune response. Since the U.S. currently lacks contemporary birth cohort data needed for such recommendations, the PREVAIL Cohort study was initiated in Cincinnati, Ohio for this purpose.

Objective:

The PREVAIL Cohort study was undertaken to define the natural history of infection and immune response to major enteric and respiratory pathogens that cause AGE and ARI in U.S. children from birth to two years of life.

Methods:

Mothers were enrolled in their third trimester of pregnancy, with intensive child follow-up to 2 years. Blood samples were obtained from children at six time points: Birth (cord), 6 weeks, and 6, 12, 18 and 24 months. Whole stool specimens and mid-turbinate nasal swabs were collected weekly and tested by multi-pathogen molecular assays. Saliva, meconium, maternal blood and milk samples were also collected. AGE (>3 loose or watery stools or >1 vomiting episode within 24 hours) and ARI (cough or fever) cases were documented by weekly cell phone surveys to mothers via automated text messaging and review of medical records. Immunization records were obtained from registries and providers. Infection for a pathogen was defined by a PCR-positive stool or nasal swab or rise in serum antibody. Enrollment of 245 mother-child pairs was completed in 2018. Follow-up of study children ends in August 2020.

Results:

Study participants were 52% white, 43% black, 56% publicly insured. Breastfeeding initiation was 86%. As of March 2020, study children were all >18 months of age and contributed 398 child-years of follow-up. Among the 193 (79%) children remaining under follow-up, median compliance was 95% for weekly text surveys; 74% for weekly samples; and 92% for post-natal blood sample collections. Blood collection was 100% for mothers and 83% for umbilical cord. By maternal report, there were 1.5 AGE and 4.3 ARI cases/child-year.

Conclusions:

This interim report demonstrates that the PREVAIL Cohort provides intensive mother-child follow-up to document the natural history of enteric and respiratory infections and immunity in children 0-2 years of age in the United States, and will contribute unique data to guide vaccine recommendations. Pathogen testing is ongoing.