Antibodies against mumps virus component proteins

Area of Science:

• Virology
• Immunology
• Vaccinology

Background:

• The neutralization (NT) test is the gold standard for detecting protective antibodies but is labor-intensive.
• Enzyme-linked immunosorbent assay (EIA) is widely used in sero-epidemiological studies due to its simplicity.
• Comparing different antibody detection methods is crucial for accurate serological assessments.

Purpose of the Study:

• To compare immunofluorescent (IF) antibodies against mumps virus nucleocapsid (N), fusion (F), and hemagglutinin-neuraminidase (HN) proteins with NT and EIA.
• To investigate the correlation between different antibody types and mumps virus proteins.
• To evaluate antibody responses after mumps vaccination.

Main Methods:

• Detection of antibodies against N, F, and HN proteins using immunofluorescence (IF).
• Comparison of IF antibody titers with results from neutralization (NT) tests and enzyme-linked immunosorbent assays (EIA).
• Analysis of serum samples from patients with previous mumps infection and from vaccinated individuals.

Main Results:

• Antibodies against the N protein were dominant in previously infected individuals.
• Many samples were EIA-positive but NT-negative, with no significant NT-EIA correlation.
• IF antibodies against N protein showed good correlation with EIA, while F and HN protein IF antibodies correlated with NT.
• Post-vaccination, EIA correlated with N protein IF antibodies, and NT-positive sera showed F and HN protein IF antibodies.

Conclusions:

• IF antibodies against F and HN proteins are strongly associated with NT antibodies, indicating a link to protective immunity.
• IF antibodies against the N protein are strongly associated with EIA, suggesting EIA may detect non-neutralizing antibodies.
• These findings highlight the importance of considering specific viral proteins when interpreting serological assays for mumps virus.