Antitoxin in human pertussis immune globulins

Area of Science:

• Immunology
• Microbiology
• Vaccinology

Background:

• Pertussis immune globulin is used for prophylaxis and therapy of whooping cough.
• Pertussis toxin (PT) is a key virulence factor in *Bordetella pertussis* infection.
• Neutralizing antibodies to PT are crucial for protection against pertussis.

Purpose of the Study:

• To determine the level of neutralizing antibodies to pertussis toxin in pertussis immune globulin preparations.
• To compare these levels with those found in individuals after natural pertussis disease.

Main Methods:

• Quantification of antitoxin (neutralizing antibodies to pertussis toxin) in six pertussis immune globulin preparations from different manufacturers.
• Comparison of antitoxin levels with convalescent phase sera from adults with natural pertussis disease.
• Measurement of agglutinin and anti-filamentous hemagglutinin (FHA) titres.

Main Results:

• Pertussis immune globulins exhibited very low antitoxin content, comparable to or lower than convalescent phase sera.
• Agglutinin and anti-FHA titres were relatively higher in immune globulins compared to convalescent sera.
• The antibody response may differ between whole-cell vaccine hyperimmunization for immune globulin production and natural pertussis infection.

Conclusions:

• The low antitoxin content in current pertussis immune globulin preparations may account for their observed inefficacy or inconsistent results in whooping cough prophylaxis and therapy.
• Further investigation into optimizing immune globulin composition for pertussis is warranted.