A recent study submitted to it The research site* preprint server, and currently under consideration in a Nature Portfolio Journal, evaluated the efficacy of REGEN-COV, a combination of casirivimab and imdevimab monoclonal antibodies, in the prevention of the severity of coronavirus disease 2019 (COVID-19) .
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines and their efficiency has played a crucial role in curbing the morbidity and mortality caused by COVID-19. However, in the wake of groundbreaking infections and reports of declining vaccine efficacy, treatment methods that can effectively prevent the severity of the disease in infected patients are crucial.
About the study
The current retrospective cohort study examined the efficacy of REGEN-COV in preventing hospitalization caused by the SARS-CoV-2 Delta variant of concern and related disease severity and death.
Data were collected from the database of Clalit Health Services (CHS), a health organization in Israel. The qualified participants were 12 years of age and older, had tested SARS-CoV-2 polymerase chain reaction (PCR) positive for the first time, had a higher risk of developing severe COVID-19, and were a member of CHS for one year from the day of infection.
The study was performed on two groups: One group included treated patients who had tested PCR-positive for the first time between 19 September 2021 and 8 December 2021 and were treated with REGEN-COV and the other group with untreated patients with a first positive result of a PCR test between 1 July 2021 and 8 December 2021 and did not receive REGEN-COV.
Each treated patient was matched with untreated patients based on age, population sector, gender, socioeconomic status, body mass index (BMI), immunosuppression status, pregnancy, and date of first vaccination dose. The date on which REGEN-COV treatment began for the treated patients was considered the index date, while the index date for an untreated patient was based on the duration between the diagnosis and administration of REGEN-COV by the matched treated patient. A secondary analysis was also performed on patients in the age group younger than 60 years and those 60 years or older.
Three results of the study were examined: the number of COVID-19-related admissions, patients suffering from severe COVID-19, and COVID-19-related deaths.
The survey results showed that a total of 162,795 CHS members tested COVID-19 positive between 1 July 2021 and 8 December 2021, of which 135,458 members were eligible for this survey. Among the qualified participants, 289 were treated with REGEN-COV and 1,294 were untreated. The median age of the selected patients was 67 years, with 49% of the patients being men.
In the REGEN-COV-treated group, the risk of COVID-19-related hospitalization was reduced by 55.2%, while the risk of COVID-19 severity was reduced by 59.4%, and the risk of death due to COVID-19 decreased by 93 , 8%.
The secondary analysis indicated that the risk of COVID-19-related hospitalization in treated patients aged 60 years or older was reduced by 55.3%, the risk of disease severity was reduced by 61.5%, and the risk of death caused by COVID -19 decreased by 95.0%. In patients under 60 years of age, the risk of COVID-19-related hospitalization was reduced by 91.5%, while the severity of COVID-19 and related death were rare in this age group.
The study results showed that REGEN-COV was quite effective in preventing COVID-19-related hospitalizations as well as reducing disease severity and related death in patients infected with the SARS-CoV-2 Delta variant.
The researchers believe that amid reports of groundbreaking infections and a reduction in the vaccine’s effect against emerging variants of the virus, treatment agents such as REGEN-COV may control further expansion of the pandemic.
Research Square * publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered as crucial, guiding clinical practice / health-related behavior or treated as established information.