Convalescent Plasma in Older Adults with COVID-19: A Systematic Review and Meta-Analysis.

Background: Among all patients infected with coronavirus disease 2019 (COVID-19), the older adult population was the most affected, with 80%-90% of fatalities occurring in this group. The effectiveness of convalescent plasma (CP) in older adults is considerably more restricted than that in adults, resulting in a demand for data on the efficacy of therapeutic CP in older adults. This meta-analysis of updated literature examined the effect of CP in older adults with COVID-19.

Methods: Relevant literature was identified from studies indexed in the Cochrane, PubMed, and Google Scholar databases between December 2019 and April 2022. The primary outcome was all-cause mortality. Risk estimates were pooled using a random-effects model. The risk of bias was assessed by regression-based Egger test using the relative risk (RR) and upper and lower confidence intervals (CIs) of the three included studies.

Results: Among 377 studies identified, three full-text studies that included 1,038 patients met the inclusion criteria. The results of our meta-analysis showed that CP administration lowered the mortality risk in older adults with COVID-19 (RR=0.47; 95% CI, 0.26-0.86; p=0.01; I2=0%, p<0.81). CP therapy was more useful if delivered early in the course of the disease (within 72 hours of onset) and in less severe stages of the disease. Mortality tended to be lower in the high-titer group.

Conclusions: CP treatment was significantly associated with a lower risk of mortality in older adults with COVID-19 than in patients not administered CP. The timing of CP administration is critical since earlier treatment after disease onset was associated with a better prognosis.