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An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection
Published on: December 10, 2013
The Humoral Immune Profiles of Infants Before and After Severe Primary RSV/A and RSV/B Infection
Vasanthi Avadhanula1, Leila C Sahni2,3, Laura Ferlic Stark1
1Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, USA.
Insights
Infants with respiratory syncytial virus (RSV) infection have low protective antibodies. RSV/A infection elicits a stronger antibody response than RSV/B, particularly in competitive antibody breadth.
Area of Science:
- Immunology
- Virology
- Pediatrics
Background:
- Infants are highly susceptible to severe respiratory syncytial virus (RSV) infections.
- Understanding the infant humoral immune response to primary RSV infection is crucial for developing effective interventions.
Purpose of the Study:
- To characterize the humoral immune response in infants hospitalized with acute respiratory infection (ARI).
- To compare the antibody response between infants with RSV-ARI and non-RSV-ARI, and against adult controls.
Main Methods:
- Enrolled hospitalized infants (RSV-ARI and controls) and adult women (controls).
- Assessed neutralizing antibodies (NtAbs) and competitive antibodies (CA) to RSV fusion (F) glycoprotein sites (Ø, I, II, IV).
- Measured anti-postF and anti-p27 IgG levels in acute and convalescent sera.
Main Results:
- Infants had low NtAbs and CA upon hospitalization.
- RSV/A infection induced broader homologous and heterologous NtAb and CA responses (sites II and IV) compared to RSV/B (site II only).
- Post-infection antibody levels in infants were lower than in adult controls.
Conclusions:
- Infants with RSV infection exhibit low pre-existing protective antibody levels.
- RSV/A infection stimulates a more robust and broader infant antibody response than RSV/B infection.
- The findings highlight differences in infant immune responses to RSV subtypes.
Introduction:
Infants are at risk of severe respiratory syncytial virus (RSV) infection. We characterized the humoral immune response of infants with primary RSV infection.
Methods:
Term infants hospitalized for RSV-acute respiratory infection (ARI) or non-RSV-ARI (controls) were enrolled from November 2018 through March 2020 at 5 pediatric medical institutions. Adult controls were women aged 18-45 years without acute RSV infection. Acute and convalescent sera were tested for homologous and heterologous neutralizing antibodies (NtAbs), competitive antibodies (CA) to sites Ø, II, IV and I on the fusion (F) glycoprotein, and anti-postF and 27 amino acid peptide (p27) IgG. Geometric mean titer or CA concentration of acute and convalescent sera were compared between and within groups.
Results:
Sixty-six infants (49 RSV infected and 17 controls) were enrolled. Median age was 76 (IQR 45-179) and 151 (IQR 72-207) days for RSV and control groups, respectively. NtAbs and CA at hospitalization were low among infant groups. Post-infection, RSV/A induced robust homologous and heterologous NtAb responses while RSV/B caused a robust NtAb response only to RSV/B. RSV/A infection generated significant CA rise to sites IV and II, while RSV/B infection resulted in only site II CA rise. Rises in postF and p27 IgG were not detected. Post-infection RSV antibody levels in infants were markedly lower compared to control adult women.
Conclusion:
RSV-infected infants had low pre-infection levels of protective antibodies. Infants infected with RSV/A compared to RSV/B generated a more robust NtAb response, highlighted by a broader CA response to sites II and IV.
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