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Updated: Aug 19, 2026
Influenza A Virus Studies in a Mouse Model of Infection
Published on: September 7, 2017
Immunogenicity of plague vaccines in mice and guinea pigs
Abstract:
The median effective doses (ED(50)) of 28 lots of killed Pasteurella pestis strain 195/P vaccine were determined in mice and guinea pigs. Mice were injected with vaccine alone, whereas guinea pigs received vaccine suspended in incomplete Freund's adjuvant. Potency ratios of vaccines were obtained by comparing the ED(50) of the test with that of a reference vaccine. Mean potency ratios of 1.82 +/- 0.50 in mice and 3.22 +/- 0.56 in guinea pigs were obtained, and the difference between these means was significant, P = <0.01. The number of organisms in the challenge dose did not significantly affect the ED(50) of a vaccine in guinea pigs. However, irrespective of vaccinating route, nearly 1,000 times as much vaccine was required in the absence of adjuvant as in its presence to produce comparable protective indexes in the guinea pig. The response of guinea pigs did not offer any improvement over mice in evaluating the efficacy of plague vaccines.
Insights
This study determined the median effective doses (ED50) for Pasteurella pestis vaccines in mice and guinea pigs. Guinea pigs showed higher potency ratios, but neither animal model offered an advantage for evaluating plague vaccine efficacy.
Area of Science:
- Immunology
- Microbiology
- Vaccinology
Background:
- Assessing the efficacy of killed Pasteurella pestis vaccines is crucial for public health.
- Standardized methods are needed to determine vaccine potency and compare different lots.
Purpose of the Study:
- To determine the median effective doses (ED50) of 28 lots of killed Pasteurella pestis strain 195/P vaccine.
- To compare the efficacy of the vaccine in mice and guinea pigs, with and without adjuvant.
Main Methods:
- Median effective doses (ED50) were determined for vaccine lots in mice and guinea pigs.
- Mice received vaccine alone; guinea pigs received vaccine with incomplete Freund's adjuvant.
- Potency ratios were calculated by comparing test vaccines to a reference vaccine.
Main Results:
- Mean potency ratios were 1.82 in mice and 3.22 in guinea pigs (P < 0.01).
- Adjuvant significantly increased vaccine efficacy in guinea pigs, requiring ~1000x less vaccine.
- Challenge dose size did not significantly impact ED50 in guinea pigs.
Conclusions:
- Both mice and guinea pigs can be used to evaluate plague vaccine efficacy.
- The use of adjuvant significantly enhances vaccine potency in guinea pigs.
- Guinea pig responses did not provide superior insights compared to mice for plague vaccine evaluation.
