Estimating Effective Vaccination Coverage with Immune Markers: Validation of anti-tetanus toxid and anti-measles IgG tests for use with dried blood spots and oral fluid samples
The development of an accurate and easy-to-use method for measuring immunologic protection against vaccine-preventable diseases (VPD) in oral fluid or dried blood spots (DBS) could transform immunization program monitoring in global health. Vaccination coverage is currently estimated using error-prone data sources of vaccination receipt, such as vaccination clinic records or parenta recall. Circulating antigen-specific IgG antibodies are immunologic markers of exposure to a pathogen or vaccine, and could be used to estimate ‘effective vaccination coverage’. However, immune marker surveillance for VPDs is currently limited by the challenges and costs of collecting venous blood from healthy kids. Our goal is to develop an accurate and field-friendly method to measure VPD immune markers from feasibly collected samples (DBS and oral fluid). Our study in Kisumu, Kenya, is currently enrolling 400 young children with known vaccination histories to test if levels of anti-measles IgG and anti-tetanus toxoid IgG can be accurately and reliably measured in oral fluid and/or DBS compared to levels in venous serum. Specimens will be collected from each child at age 12 months and 24 months. The results of the study will provide rigorous evidence about the utility of DBS and oral fluid testing for vaccination surveillance.
Global Health Mentor: Kyla Hayford