ABSTRACT
Background and aims Immunocompromised patients have a reduced ability to generate antibodies after COVID-19 vaccination and are at higher risk of SARS-CoV-2 infection, complications and mortality. Tixagevimab/Cilgavimab (Evusheld) is a monoclonal antibody combination which bind to the SARS-CoV-2 spike protein, preventing the virus entering human cells. The phase III PROVENT trial reported that immunocompromised patients given Tixagevimab/Cilgavimab had a significantly reduced risk of COVID-19 infection. However, PROVENT was conducted before the SARS-CoV-2 Omicron became prevalent. This systematic review provides an updated summary of real-world clinical evidence of Tixagevimab/Cilgavimab effectiveness in immunocompromised patients. Methods Two independent reviewers conducted PubMed and medRxiv searches for the period of 01/01/2021 to 01/10/2022. Clinical studies which reported the primary outcome of breakthrough COVID-19 infections after Tixagevimab/Cilgavimab administration were included in the review. COVID-19-related hospitalisations, ITU admissions and mortality were assessed as secondary outcomes. Clinical effectiveness was determined using the case-control clinical effectiveness methodology. The GRADE tool was used to ascertain the level of certainty for the primary outcome in each study. Results 17 clinical studies were included, comprising 24,773 immunocompromised participants of whom 10,775 received Tixagevimab/Cilgavimab. Most studies reported clinical outcomes during the SARS-CoV-2 Omicron wave. Six studies compared a Tixagevimab/Cilgavimab intervention group to a control group. Overall, the clinical effectiveness of prophylactic Tixagevimab/Cilgavimab against COVID-19 breakthrough infection, hospitalisation and ITU admission were 40.47%, 69.23% and 87.89%, respectively. For prevention of all-cause and COVID-19-specifc mortality, overall clinical effectiveness was 81.29% and 86.36%, respectively. Conclusions There is a growing body of real-world evidence validating the original PROVENT phase III study regarding the clinical effectiveness of Tixagevimab/Cilgavimab as prophylaxis for immunocompromised patients, notably demonstrating effectiveness during the Omicron wave. This review demonstrates the clinical effectiveness of prophylactic Tixagevimab/Cilgavimab at reducing COVID-19 infection, hospitalisation, ITU admission and mortality for immunosuppressed individuals. It is important that ongoing larger-scale and better-controlled real world studies are initiated and evaluated to provide ongoing certainty of the clinical benefit of prophylactic antibody treatment for immunocompromised patients in the face of new variants.
Subject(s)
COVID-19 , Breakthrough PainABSTRACT
Background: Lateral flow devices (LFDs) are viral antigen tests for the detection of SARS-CoV-2 that produce a rapid result, are inexpensive and easy to operate. They have been advocated for use by the World Health Organisation to help control outbreaks and break the chain of transmission of COVID-19 infections. There are now several studies assessing their accuracy but as yet no systematic review. Our aims were to assess the sensitivity and specificity of LFDs in a systematic review and summarise the sensitivity and specificity of these tests. Methods: A targeted search of Pubmed and Medxriv, using PRISMA principles, was conducted identifying clinical studies assessing the sensitivity and specificity of LFDs as their primary outcome compared to reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of SARS-CoV-2. Based on extracted data sensitivity and specificity was calculated for each study. Data was pooled based on manufacturer of LFD and split based on operator (self-swab or by trained professional) and sensitivity and specificity data were calculated. Results: Twenty-four papers were identified involving over 26,000 test results. Sensitivity from individual studies ranged from 37.7% (95% CI 30.6-45.5) to 99.2% (95% CI 95.5-99.9) and specificity from 92.4% (95% CI 87.5-95.5) to 100.0% (99.7-100.0). BD Veritor was the best performing manufacturer of LFD with a sensitivity of 99.2% (95% CI 95.5-99.9) and specificity of 100.0% (98.9-100.0). Operation of the test by a trained professional or by the test subject with self-swabbing produced comparable results. Conclusions: This systematic review identified that the performance of lateral flow devices is heterogeneous and dependent on the manufacturer. Some perform with high specificity with reasonable sensitivity. Test performance does appear dependent on the operator. Potentially, LFDs could support the scaling up of mass testing to aid track and trace methodology and break the chain of transmission of COVID-19 with the additional benefit of providing individuals with the results in a much shorter time frame.