Evaluation of the protective efficacy of recombinant protective antigen vaccine (GC1109)-immunized human sera using passive immunization in a mouse model

Su Kyoung Jo; Bo-Eun Ahn; Eun Hye Choi; Ji Eun Kang; Hyonggin An; Myoung-Don Oh; Gi-Eun Rhie

doi:10.1016/j.vaccine.2019.12.048

Evaluation of the protective efficacy of recombinant protective antigen vaccine (GC1109)-immunized human sera using passive immunization in a mouse model

Vaccine. 2020 Feb 11;38(7):1586-1588. doi: 10.1016/j.vaccine.2019.12.048. Epub 2020 Jan 3.

Authors

Su Kyoung Jo¹, Bo-Eun Ahn¹, Eun Hye Choi¹, Ji Eun Kang², Hyonggin An³, Myoung-Don Oh⁴, Gi-Eun Rhie⁵

Affiliations

¹ Division of High-risk Pathogens, Center for Laboratory Control of Infectious Diseases, Korea Centers for Disease Control and Prevention, Cheongju, South Korea.
² Downstream Process Ⅱ, Research Center, GC Pharma, Yongin, South Korea.
³ Department of Biostatistics, College of Medicine, Korea University, Seoul, South Korea.
⁴ Department of Internal Medicine, Seoul National University College of Medicine, Seoul, South Korea; Department of Internal Medicine, Seoul National University Hospital, Seoul, South Korea.
⁵ Division of High-risk Pathogens, Center for Laboratory Control of Infectious Diseases, Korea Centers for Disease Control and Prevention, Cheongju, South Korea. Electronic address: [email protected].

PMID: 31911031
DOI: 10.1016/j.vaccine.2019.12.048

Abstract

The protective efficacy of human sera from vaccinated individuals with a new recombinant protective antigen anthrax vaccine (GC1109) against lethal spore challenge was evaluated in a mouse model. Eighteen human sera were selected from the vaccinated individuals based on their toxin neutralizing assay (TNA) titer (ED₅₀ of 55 to 668). The selected sera were diluted and passively transferred to A/J mice and the mice were subsequently challenged with 100 × LD₅₀ of Bacillus anthracis Sterne spores. The correlation between the survival rate of passively immunized mice and the TNA ED₅₀ of transferred sera was presented (r = 0.873, P-value < 0.001). The estimated TNA titer for 50% survival rate against lethal challenge was 197 (95% confidence interval of 149 and 260). The result suggest that GC1109 is protective against exposure to B. anthracis and the TNA titer of vaccinated serum can be an indicator for protective efficacy.

Keywords: Anthrax vaccine; Passive immunization; Survival rate; Toxin neutralization assay.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Anthrax Vaccines / administration & dosage*
Anthrax Vaccines / immunology*
Anthrax* / prevention & control
Antibodies, Bacterial
Antigens, Bacterial
Bacillus anthracis / immunology
Humans
Immunization, Passive*
Mice
Neutralization Tests

Substances

Anthrax Vaccines
Antibodies, Bacterial
Antigens, Bacterial