The effectiveness of tixagevimab/cilgavimab for prevention of SARS-CoV-2 an infection and extreme illness amongst immunocompromised sufferers
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A latest article posted to the medRxiv* preprint server assessed the efficiency of tixagevimab/cilgavimab in averting extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) an infection in vaccinated immunocompromised folks.

Study: Tixagevimab/Cilgavimab for Prevention of COVID-19 in the course of the Omicron Surge: Retrospective Analysis of National VA Electronic Data. Image Credit: Cinefootage Visuals/Shutterstock


CoV illness 2019 (COVID-19) is related to a excessive threat of mortality and morbidity in immunocompromised folks. While COVID-19 vaccines have helped halt SARS-CoV-2 unfold and cut back the danger of extreme sickness within the basic inhabitants, immunocompromised individuals are nonetheless at excessive threat of steady viral replication and breakthrough infections.

A Phase III, randomized, placebo-controlled, multicenter trial, the PROVENT investigation, confirmed a single intramuscular tixagevimab/cilgavimab dose considerably decreased symptomatic COVID-19 incidence by 76.7% following 90 days in a big pattern of adults with an elevated threat of inadequate vaccination response or SARS-CoV-2 publicity.

Relying on these outcomes, on 8 December 2021, the United States (US) Food and Drug Administration (FDA) supplied tixagevimab/cilgavimab an emergency use authorization (EUA) as a pre-exposure prophylactic for reasonable or severely immunocompromised folks or for whom vaccination with any current SARS-CoV-2 vaccine isn’t suggested due to a extreme antagonistic response historical past. However, the efficacy of tixagevimab/cilgavimab in stopping COVID-19 in vaccinated immunocompromised people is unsure, particularly following the emergence of the SARS-CoV-2 Omicron pressure.

About the examine

The current retrospective cohort analysis aimed to research the efficacy of tixagevimab/cilgavimab in stopping COVID-19 and extreme SARS-CoV-2 an infection throughout COVID-19 vaccinated immunodeficient sufferers by way of difference-in-difference analyses (DiD) and propensity matching. The examine was carried out utilizing the digital information from the Department of Veterans Affairs (VA) healthcare system within the US, probably the most complete healthcare community within the US, of Veterans aged 18 or older as of 1 January 2022 who had been getting VA medical care. 

The researchers in contrast a gaggle of 1,848 sufferers who obtained a minimal of one intramuscular dose of tixagevimab/cilgavimab with matched controls recognized from 251,756 sufferers who had been immunodeficient or had been at elevated threat for SARS-CoV-2 an infection. Patients had been monitored via 30 April 2022 or until demise, whichever got here first. The investigation’s key outcomes had been a COVID-19 composite, SARS-CoV-2-linked hospitalization, and all-cause demise. The group employed Cox proportional hazards modeling to calculate the hazard ratios (HR) and 95% confidence intervals (CI) for the hyperlink between tixagevimab/cilgavimab use and outcomes.

On the entire, within the present examine, the scientists decided the real-world efficacy of tixagevimab/cilgavimab in stopping COVID-19, SARS-CoV-2-related hospitalization, and all-cause demise in COVID-19 vaccinated immunocompromised Veterans.

Findings and discussions

Overall, the examine outcomes confirmed that 69% of Veterans who obtained tixagevimab/cilgavimab had been 65 years or older, 92% had been acknowledged as immunodeficient by digital information, and 73% bought ≥ three doses of COVID-19 messenger ribonucleic acid (mRNA) vaccine or two Ad26.COV2 doses. Before receiving tixagevimab/cilgavimab, virtually all (95%) of the examine members had obtained a minimal of two COVID-19 mRNA vaccine doses or one Ad26.COV2 dose.

Tixagevimab/cilgavimab-treated sufferers had a notably decreased incidence of the composite SARS-CoV-2 an infection end result (17/1733 versus 206/6354), in addition to COVID-19, SARS-CoV-2-associated hospitalization, and all-cause demise relative to propensity-matched controls. The current outcomes had been invariant over two strong statistical strategies, together with DiD estimations and propensity rating matching.

Since these findings had been noticed amongst reasonable to severely immunocompromised and older sufferers, they backed up the EUA tips for tixagevimab/cilgavimab use on this cohort. The investigators found that absolutely vaccinated (a minimum of two doses) immunocompromised sufferers administered tixagevimab/cilgavimab had enhanced safety towards COVID-19, much like absolutely boosted (major vaccination routine plus a booster dose) non-immunocompromised adults. 

While tixagevimab/cilgavimab retained neutralization towards the SARS-CoV-2 Delta variant, they’d a decrease neutralizing impact towards the Omicron BA.1 variant, urging the FDA to revise the EUA to extend tixagevimab/cilgavimab’s preliminary dose. Further, present proof illustrated that tixagevimab/cilgavimab retained neutralization towards Omicron BA.2.12.1 and BA.2 variants, albeit their efficacy is perhaps diminished with Omicron BA.5 and BA.4 strains. In addition, the authors famous that the trial had immortal time bias and indication confounding.


According to the scientists, this analysis provided the preliminary real-world proof of tixagevimab/cilgavimab’s potential in stopping SARS-CoV-2 an infection and worthwhile details about the affected person inhabitants who obtained tixagevimab/cilgavimab all through the VA healthcare community.

Overall, within the current work, using nationwide US real-world information from principally vaccinated, immunodeficient Veterans, the authors discovered utilizing tixagevimab/cilgavimab in the course of the Omicron surge interval was linked with diminished COVID-19, SARS-CoV-2-related hospitalization, and all-cause demise charges. These outcomes recommended that along with COVID-19 vaccination, tixagevimab/cilgavimab therapy safeguards vulnerable people from COVID-19 and extreme SARS-CoV-2 an infection within the present section of the pandemic. 

The examine confirmed that solely a tiny share of eligible topics obtained tixagevimab/cilgavimab remedy, implying that extra outreach and schooling had been wanted to establish that extra immunodeficient Veterans all through the VA healthcare community obtained tixagevimab/cilgavimab, notably throughout SARS-CoV-2 outbreaks. Besides, the authors said that continued real-world information would possibly support within the understanding of tixagevimab/cilgavimab’s effectiveness for pre-exposure COVID-19 prophylaxis throughout time and towards new SARS-CoV-2 variants. 

*Important discover

medRxiv publishes preliminary scientific reviews that aren’t peer-reviewed and, due to this fact, shouldn’t be considered conclusive, information medical follow/health-related conduct, or handled as established info.

Journal reference:

  • Young-Xu, Y. et al. (2022) “Tixagevimab/Cilgavimab for Prevention of COVID-19 during the Omicron Surge: Retrospective Analysis of National VA Electronic Data”. medRxiv. doi: 10.1101/2022.05.28.22275716. material/10.1101/2022.05.28.22275716v1

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