Development and comparison of immunologic assays to detect primary RSV infections in infants

Larry J Anderson1,2, Samadhan J Jadhao1,2, Laila Hussaini1,2

  • 1Division of Infectious Diseases, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States.

Frontiers in Immunology
|January 29, 2024
PubMed

Insights

Sensitive assays are crucial for tracking respiratory syncytial virus (RSV) immunity in children. The study found that lysate and F protein IgG enzyme immunoassays (EIAs) are most effective for detecting past RSV infection in young children.

Area of Science:

  • Immunology
  • Vaccinology
  • Pediatrics

Background:

  • Respiratory syncytial virus (RSV) vaccines are available for adults and pregnant women, but not yet for infants and young children.
  • Determining a young child's RSV immune status is vital for epidemiological studies and vaccine clinical trials.
  • Sensitive assays are needed to detect immunologic evidence of past RSV infection in children.

Purpose of the Study:

  • To develop, characterize, and evaluate seven different assays for detecting immunologic evidence of past RSV infection in young children.
  • To identify the most sensitive and reliable assays for use in pediatric RSV epidemiology and vaccine research.

Main Methods:

  • Developed and evaluated four IgG enzyme immunoassays (EIAs) using lysate, F protein, G protein A, or G protein B antigens.
  • Assessed two neutralizing antibody assays (subgroup A and B) and one IFN-γ EliSpot assay.
  • Tested assay performance including repeatability, limit of detection, and interference from sample conditions.

Main Results:

  • In children with documented RSV illness, lysate and F protein IgG EIAs showed 100% sensitivity.
  • Neutralizing antibody assays had lower sensitivity (43-57%), while G protein EIAs varied (86-95%).
  • The EliSpot assay showed unexpected positivity in infants without recent RSV exposure, possibly due to maternal microchimerism.

Conclusions:

  • Lysate and F protein IgG EIAs are highly sensitive and reliable for detecting RSV antibodies in young children.
  • These assays are suitable for use in pediatric RSV epidemiologic studies and vaccine trials.
  • Further investigation into the EliSpot assay's reactivity in infants may be warranted.