Intestinal antibody responses after immunisation with cholera B subunit

Area of Science:

• Immunology
• Vaccinology
• Infectious Diseases

Background:

• Cholera remains a significant public health concern, necessitating effective vaccination strategies.
• Understanding the mucosal immune response to cholera vaccines is crucial for developing optimal delivery methods.

Purpose of the Study:

• To evaluate the local intestinal secretory immunoglobulin A (IgA) antitoxin response to a novel cholera toxoid immunogen (B subunit).
• To compare the immunogenicity of oral versus intramuscular administration of the cholera toxoid immunogen.

Main Methods:

• A single oral or intramuscular immunisation with a cholera toxoid immunogen (B subunit) was administered to Bangladeshi volunteers.
• Intestinal secretory IgA antitoxin levels in intestinal-lavage fluid were measured using enzyme-linked immunosorbent assay (ELISA).
• Responses after a second immunisation were also assessed.

Main Results:

• Approximately 80% of volunteers developed an intestinal secretory IgA antitoxin response following a single immunisation.
• Both oral and intramuscular routes elicited comparable IgA antitoxin titres, similar to those observed after clinical cholera.
• The IgA antitoxin response persisted longer after oral immunisation than after intramuscular immunisation.
• A second immunisation, regardless of route, typically elicited a response similar to the first.

Conclusions:

• The novel cholera toxoid immunogen (B subunit) effectively induces a local intestinal IgA antitoxin response.
• Oral administration may offer advantages due to a more sustained immune response compared to intramuscular delivery.
• The findings support the potential of this cholera toxoid immunogen for cholera prevention.