Abstract:
Background During the COVID-19 pandemic, some populations, including immunocompromised patients, could
not tolerate COVID-19 vaccination or had low responses. Evusheld is a combined neutralizing monoclonal antibody
containing tixagevimab and cilgavimab. The World Health Organization (WHO) has approved this combination as preexposure prophylaxis (PrEP) and treatment for immunocompromised patients. With the new variant, the (WHO)
recommended an increase in dose from 300 to 600 mg with a booster dose after 6 months. The target of this review
was to compare the efcacy of the two doses, 300 mg and 600 mg of tixagevimab/cilgavimab (Evusheld) as prophy‑
laxis for higher-risk individuals to reveal if there is a signifcant diference in efcacy between those two doses
of the drug.
Methods In this study, electronic databases (PubMed, Web of Science core collection, Scopus, and Cochran) were
investigated for articles up to 31/12/2022 in English using a well-established search strategy. We included studies
conducted in immunocompromised patients (aged≥12 years) (WHO) received Evusheld as prophylaxis or treatment
for COVID-19. After excluding studies inconsistent with the selection criteria, 24 were involved, 22 of which were
included in the meta-analysis. We analyzed the data by using RevMan 5.4 program software.
Results In the double-arm subgroup analysis, Evusheld 600 mg, administered as prophylaxis, showed no signifcant
diference in the COVID-19 infection rate, mortality rate, or needed hospitalization rate compared with the dose
of 300 mg (p=0.13, p=0.29, and p=0.25, respectively). In the single-arm subgroup analysis, Evusheld 600 mg,
administered as prophylaxis, showed a signifcant decrease in the COVID-19 infection rate and the hospitalization rate
compared with the dose of 300 mg (p=0.0001, p=0.007, respectively). As a treatment, Evusheld showed a signifcant
decrease in the mortality rate over the placebo group (p=0.01) in COVID-19 patients.
Conclusion This result indicated that Evusheld was an efective prophylactic and therapeutic drug for COVID-19
infection, especially for immunocompromised patients, but there was no considerable variation between the high
and low doses. Further prospective and randomized controlled trials (RCTs) with increased population sizes are neces‑
sary to show the valuable beneft of the high dose of Evusheld in COVID-19 prevention and treatment and to com‑
pare the diference between the two doses within adverse events.
