Immunogenicity and safety of tixagevimab-cilgavimab for COVID-19 pre-exposure prophylaxis in immunocompromised 20 to <40 kg children and adolescents: A pilot, prospective, open-labeled study
1
Issued Date
2024-01-01
Resource Type
ISSN
21645515
eISSN
2164554X
Scopus ID
2-s2.0-85210071402
Journal Title
Human Vaccines and Immunotherapeutics
Volume
20
Issue
1
Rights Holder(s)
SCOPUS
Bibliographic Citation
Human Vaccines and Immunotherapeutics Vol.20 No.1 (2024)
Suggested Citation
Buaboonnam J., Rungmaitree S., Piyaphanee N., Charuvanij S., Pitisuttithum O., Copeland K., Pheerapanyawaranun C., Jansarikit L., Niyomnaitham S., Chokephaibulkit K. Immunogenicity and safety of tixagevimab-cilgavimab for COVID-19 pre-exposure prophylaxis in immunocompromised 20 to <40 kg children and adolescents: A pilot, prospective, open-labeled study. Human Vaccines and Immunotherapeutics Vol.20 No.1 (2024). doi:10.1080/21645515.2024.2428011 Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/102239
Title
Immunogenicity and safety of tixagevimab-cilgavimab for COVID-19 pre-exposure prophylaxis in immunocompromised 20 to <40 kg children and adolescents: A pilot, prospective, open-labeled study
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Abstract
We evaluated the immunogenicity of 300 mg Tixagevimab-Cilgavimab in immunocompromised children and adolescents who weighed 20 to >40 kg. Six to 18-year-old participants were divided into two groups by body weight and received 300 mg (20 to <40 kg) and 600 mg (≥40 kg) Tixagevimab-Cilgavimab, respectively. Anti-SARS-CoV-2 receptor-binding domain IgG concentrations and pseudovirus neutralizing antibody (NAb) titers were measured at 4, 12, and 24 weeks after administration and compared with reference data from healthy Thai children at 2 weeks after three BNT162b2 vaccinations. Of 59 participants, 49.2% were female, with a median (IQR) age of 12 (9, 15) years; 16 (27.1%) had cancer. NAb titers (95% CI) for the ancestral Wuhan strain were comparatively high for both dosing regimens (16363.2 [13765.9, 19450.5] vs 17768.3 [15539.5, 20316.9] in 20 to <40 kg and ≥40 kg participants, respectively) and significantly higher than reference titers (P < 0.001 for both). NAb titers for Omicron BA.4/5 were on par with the reference for both dosing regimens. Adverse events were mild, well tolerated, and slightly more prevalent in ≥40 kg participants who received full-dose Tixagevimab–Cilgavimab. Minimal waning in anti-RBD IgG concentrations, comparable to the reference, was observed at 12 and 24 weeks after Tixagevimab-Cilgavimab administration for both regimens. We concluded that half-dose Tixagevimab-Cilgavimab in 20 to <40 kg participants generated equivalent antibodies to standard doses in ≥40 kg participants and significantly higher antibodies than three-dose BNT162b2 vaccination. Further study of monoclonal long-acting antibodies in larger cohorts and <6-year-old children are warranted.