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The immune response in primary asymptomatic and symptomatic rotavirus infection in newborn infants
1Department of Pediatrics, University of Maryland, Baltimore 21201.
Insights
In infants with rotavirus infections, IgA antibodies were prominent, especially in asymptomatic cases. This suggests mucosal immunity plays a key role in protecting young children from rotavirus.
Area of Science:
- Immunology
- Virology
- Pediatrics
Background:
- Rotavirus is a leading cause of severe diarrhea in infants globally.
- Understanding the immune response to primary rotavirus infection in neonates is crucial for developing effective vaccines and interventions.
- Infant immune systems are still developing, leading to unique responses to infections.
Purpose of the Study:
- To investigate systemic and mucosal immune responses in infants with primary rotavirus infections.
- To identify key antibody types involved in rotavirus infection outcomes in neonates.
- To explore the role of mucosal immunity in asymptomatic rotavirus infections.
Main Methods:
- Enzyme-linked immunosorbent assay (ELISA) was used to measure antibody responses.
- Systemic (serum) and mucosal (fecal) samples were collected from infants aged 7-86 days.
- Rotavirus serotyping was performed on isolates from infected infants.
Main Results:
- Most infected infants (15/18) were asymptomatic; 3 experienced diarrhea.
- IgA antibodies were detected in the serum of 4 asymptomatic and all symptomatic infants.
- Rotavirus-specific fecal antibody responses were observed in 73% of asymptomatic and all symptomatic infants.
- No significant neutralization antibody rise to serotype 1 was detected in the limited samples tested.
Conclusions:
- Immunoglobulin A (IgA) is a critical antibody during primary rotavirus infection in young infants.
- The prevalence of IgA in asymptomatic infants suggests a significant role for mucosal immunity in protection.
- Mucosal immune responses may be key to protection against rotavirus upon reexposure.
Abstract:
Systemic and mucosal immune responses were determined using an enzyme-linked immunosorbent assay in 18 infants (7-86 days old) experiencing primary rotavirus infections over two winters. Fifteen infected infants were asymptomatic; 3 had diarrhea. Neutralization antibody (NA) was assayed in two asymptomatic infants who had a serotype 1 isolate identified. Seven asymptomatic infants had sera available for analysis; none had IgG, 1 had IgM, but 4 had IgA antibody responses. Neither tested infant had a serotype 1 NA rise. In the 3 symptomatic infants, 1 had IgG, 2 had IgM, and all had IgA serum antibody responses detected. Eleven (73%) of 15 asymptomatic and all symptomatic infants had a rotavirus-specific fecal antibody response. These findings identify IgA as an important antibody in primary rotavirus infection in very young infants. The predominance of this antibody in asymptomatic infants suggests that their responses (and protection on subsequent reexposure) may be primarily mucosal.