Related Experiment Video
Updated: Aug 14, 2026

In Vivo Assay for Detection of Antigen-specific T-cell Cytolytic Function Using a Vaccination Model
Published on: November 28, 2017
Real-world experience of tixagevimab/cilgavimab prophylaxis in Japanese patients with immunodeficiency
Kento Inoue1, Dan Tomomasa1, Yu Nakagama2
1Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Institute of Science Tokyo, 1-5-45 Yushima, Bunkyo-ku, 113-8519, Tokyo, Japan.
Background:
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes severe illness and mortality in patients with immunodeficiency. Although vaccination has been recommended, the induction of protective antibodies by immunization, and thus the disease-preventive effect, has proven insufficient in immunodeficient patients, especially in those with predominantly antibody deficiency. A monoclonal antibody combination of tixagevimab and cilgavimab (TIX/CIL) was developed as a pre-exposure prophylaxis (PrEP). In this study, we investigated the post-PrEP increase in antiviral antibody titers and detailed the breakthrough infections that occurred despite PrEP in Japanese immunodeficient patients who had received TIX/CIL.
Methods:
Blood samples were collected before and after TIX/CIL administration between November 2022 and August 2023. Antibody titers against the S-protein of SARS-CoV-2 were measured to evaluate TIX/CIL-induced protection. Information regarding breakthrough infection, as evidenced by positive antigen and/or PCR tests, was collected.
Results:
A significant increase in the anti-S antibody titer was observed in all 89 immunodeficient patients who had received TIX/CIL. However, 14 (16 %) patients experienced breakthrough SARS-CoV-2 infections, of which one died of respiratory failure.
Conclusion:
The shift in the SARS-CoV-2 circulating strain might have reduced the efficacy of TIX/CIL, leading to an increased number of breakthrough infections.
More Related Videos
09:37Detection of Polyfunctional T Cells in Children Vaccinated with Japanese Encephalitis Vaccine via the Flow Cytometry Technique
Published on: September 23, 2022
06:22Standardization of Transfer across Labs between Flow Cytometers for Detection of Lymphocytes in Japanese Encephalitis Vaccinated Children
Published on: February 10, 2023
Related Concept Videos
Cytotoxic T Cells-mediated Immune Response
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...
Immunological Memory
What is Immunological Memory?
Immunological memory is an integral function of the immune system that allows it to recognize and react more rapidly and effectively to pathogens previously encountered. This feature is...
Development of Immunocompetence
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
Immunodeficiency Diseases
There are three main causes of immunodeficiency disorders...
Drugs for Treatment of Crohn's Disease in IBD Using Immunomodulatory Agents
Cytomegalovirus Disease