Tixagevimab/cilgavimab (TGM/CGM) are neutralizing monoclonal antibodies (mAbs) directed against different epitopes of the receptor-binding domain of the SARS-CoV-2 spike protein that have been considered as pre-exposure prophylaxis (PrEP). This study seeks to assess the efficacy and safety of TGM/CGM to prevent COVID-19 in patients at high risk for breakthrough and severe SARS-CoV-2 infection who never benefited maximally from SARS-CoV-2 vaccination and for those who have a contraindication to SARS-CoV-2 vaccines. This study is a systematic review and meta-analysis. The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement was followed. Electronic databases (PubMed, CINAHL, Embase, medRxiv, ProQuest, Wiley online library, Medline, and Nature) were searched from 1 December 2021 to 30 November 2022 in the English language using the following keywords alone or in combination: 2019-nCoV, 2019 novel coronavirus, COVID-19, coronavirus disease 2019, SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, tixagevimab, cilgavimab, combination, monoclonal, passive, immunization, antibody, efficacy, clinical trial, cohort, pre-exposure, prophylaxis, and prevention. We included studies in moderate to severe immunocompromised adults (aged ≥18 years) and children (aged ≥12 years) who cannot be vaccinated against COVID-19 or may have an inadequate response to SARS-CoV-2 vaccination. The effect sizes of the outcome of measures were pooled with 95% confidence intervals (CIs) and risk ratios (RRs). Of the 76 papers that were identified, 30 articles were included in the qualitative analysis and 13 articles were included in the quantitative analysis (23 cohorts, 5 case series, 1 care report, and 1 randomized clinical trial). Studies involving 27,932 patients with high risk for breakthrough and severe COVID-19 that reported use of TGM/CGM combination were analyzed (all were adults (100%), 62.8% were men, and patients were mainly immunocompromised (66.6%)). The patients' ages ranged from 19.7 years to 79.8 years across studies. TGM/CGM use was associated with lower COVID-19-related hospitalization rate (0.54% vs. 1.2%, p = 0.27), lower ICU admission rate (0.6% vs. 5.2%, p = 0.68), lower mortality rate (0.2% vs. 1.2%, p = 0.67), higher neutralization of COVID-19 Omicron variant rate (12.9% vs. 6%, p = 0.60), lower proportion of patients who needed oxygen therapy (8% vs. 41.2%, p = 0.27), lower RT-PCR SARS-CoV-2 positivity rate (2.1% vs. 5.8%, p < 0.01), lower proportion of patients who had severe COVID-19 (0% vs. 0.5%, p = 0.79), lower proportion of patients who had symptomatic COVID-19 (1.8% vs. 6%, p = 0.22), and higher adverse effects rate (11.1% vs. 10.7%, p = 0.0066) than no treatment or other alternative treatment in the prevention of COVID-19. For PrEP, TGM/CGM-based treatment can be associated with a better clinical outcome than no treatment or other alternative treatment. However, more randomized control trials are warranted to confirm our findings and investigate the efficacy and safety of TGM/CGM to prevent COVID-19 in patients at risk for breakthrough or severe SARS-CoV-2 infection.