Affiliations

• ¹ Better Outcomes Registry and Network (BORN) Ontario, Children's Hospital of Eastern Ontario Research Institute, 401 Smyth Road, Ottawa, ON, Canada K1H 8L1 dfell@bornontario.ca.
• ² Perinatal Epidemiology Research Unit, Departments of Obstetrics and Gynaecology and Pediatrics, Dalhousie University, Halifax, NS, Canada B3K 6R8.
• ³ Canadian Centre for Vaccinology, Dalhousie University, Halifax, NS, Canada B3K 6R8.