Evaluation of Neutralizing Capacity of Tixagevimab plus Cilgavimab (AZD7442) against Different SARS‐CoV‐2 Variants: A Case Report Study with Comparison to a Vaccinated Population

• Published in: Case reports in infectious diseases Vol. 2024; no. 1; p. 9163490
• Main Authors: Gillot, Constant, Bayart, Jean-Louis, Maloteau, Vincent, Dogné, Jean-Michel, Douxfils, Jonathan, Favresse, Julien
• Format: Journal Article
• Language: English
• Published: Egypt John Wiley & Sons, Inc 2024; Wiley
• Subjects: Antibodies; Case Report; Case reports; Cell culture; COVID-19 vaccines; Electronic components industry; Health aspects; Monoclonal antibodies; Patients; Pharmaceutical industry; Proteins; Severe acute respiratory syndrome coronavirus 2; Vaccination; Viral antibodies; Belgium; United States; United Kingdom; United States > US
• ISSN: 2090-6625; 2090-6633
• DOI: 10.1155/2024/9163490

AZD7442 (150 mg of tixagevimab plus 150 mg of cilgavimab) has been approved for the preexposure prophylaxis of COVID‐19 and for the treatment of adults and adolescents with COVID‐19 who do not require supplemental oxygen and who are at increased risk of severe COVID‐19. Thus, the aim of the present study is to evaluate the neutralizing capacity of tixagevimab and cilgavimab across different SARS‐CoV‐2 variants in two patients who received AZD7442 for immunoprophylaxis. A cohort of subjects ( n  = 45) who had received the BNT162b2 mRNA COVID‐19 vaccine has been included to compare these two preventive strategies. Neutralizing antibody (NAb) titers against several variants were assessed against the wild‐type, alpha, beta, gamma, delta, omicron BA.5, and XBB.1.5 variants. Binding antibodies have also been measured. NAbs T 1/2 for AZD7442 was 8.1 days (95% CI: 5.1–19.5 days) and was 11.8 days (95% CI: 7.9–23.7 days) for the primo‐vaccination cohort. The time to reach neutralization negativity was 108.3 days (95% CI: 66.9–130.7) for AZD7442 compared to 95.4 days (95% CI: 31.0–119.7 days) for the primo‐vaccination cohort. The time to reach NAbs’ negativity differs between variants with the maximum value obtained for alpha (i.e., 101.1 days (95% CI: 30.0–135.4 days)) and the minimum obtained for beta (i.e., 61.2 days (95% CI: 37.8–77.1 days)). Our results reinforce the need of reviewing the use of AZD7442 in relation to variants of concern and potentially adapting its administration schedule. AZD7442 could be indicated for short‐term prophylaxis in frail patients who may be acutely exposed to SARS‐CoV‐2.