Development of a new neutralization test for measles virus

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Accurate measles immunity assessment is crucial for identifying susceptible populations.
• Traditional serological tests like hemagglutination inhibition (HI) lack sensitivity.
• Current methods like particle agglutination (PA) and enzyme-linked immunosorbent assay (EIA) are used, but the gold standard neutralization test (NT) is laborious.

Purpose of the Study:

• To develop a simplified and efficient measles neutralization test.
• To evaluate a novel approach using a recombinant measles virus expressing green fluorescent protein (GFP-MVAIK).
• To compare the performance of this new method with established measles antibody detection assays.

Main Methods:

• Construction of a recombinant measles AIK-C virus expressing GFP (GFP-MVAIK) for use as a challenge virus.
• Visualization of viral plaques and cytopathic effects under ultraviolet light.
• Quantification of fluorescence intensity to determine neutralizing antibody titers.
• Comparison with hemagglutination inhibition (HI), particle agglutination (PA), enzyme-linked immunosorbent assay (EIA), and a complete inhibition neutralization test.

Main Results:

• The GFP-MVAIK based neutralization test simplified plaque and cytopathic effect detection.
• Neutralizing antibody titers obtained were equivalent to those from a 90% plaque reduction neutralization test.
• Enzyme-linked immunosorbent assay (EIA) results showed good correlation with the complete inhibition neutralization test.
• Borderline EIA results occasionally yielded negative outcomes in the complete inhibition neutralization assay.

Conclusions:

• A recombinant fluorescent measles virus facilitates a simplified and faster neutralization test.
• This improved method offers a reliable alternative for measles immunity assessment.
• The new assay shows promise for sero-epidemiological studies to identify measles-susceptible populations.