Highly sensitive histamine-sensitization test for residual activity of pertussis toxin in acellular pertussis vaccine

Area of Science:

• Pharmacology
• Immunology
• Vaccine Development

Background:

• The histamine-sensitization test is crucial for quantifying residual pertussis toxin in acellular pertussis vaccines.
• Current methods rely on mouse mortality, which is influenced by mouse sensitivity, and a rectal temperature method used in Japan has limited international feasibility.
• There is a need for a sensitive, reproducible, and less invasive method for vaccine potency testing.

Purpose of the Study:

• To evaluate a novel dermal temperature measurement method using infrared thermometers as an alternative to rectal temperature measurement for assessing acellular pertussis vaccine activity.
• To determine if the dermal temperature method offers comparable sensitivity and consistency to the established rectal temperature method.
• To explore a method that potentially reduces animal suffering in vaccine testing.

Main Methods:

• Mice were injected with acellular pertussis vaccine formulations.
• Dermal temperature was measured using an infrared thermometer.
• Rectal temperatures were also recorded for comparison.
• Vaccine activity was assessed by comparing temperature changes relative to a reference preparation.

Main Results:

• The dermal temperature measurement method demonstrated sensitivity comparable to the traditional rectal temperature method.
• Both dermal and rectal temperature methods allowed for relative evaluation against a reference preparation, enabling inter-laboratory comparisons.
• Results obtained using the dermal temperature method showed good consistency with those from the rectal temperature method.

Conclusions:

• Infrared-based dermal temperature measurement is a viable and sensitive alternative for evaluating acellular pertussis vaccine activity.
• This method offers a less invasive approach, potentially reducing animal welfare concerns compared to rectal temperature measurements.
• The dermal temperature method provides a reliable and consistent means for assessing vaccine potency across different laboratories.