Table 1.

Clinical research of Tα1 on COVID-19.

Dosage Regimen	Subjects with Tα1/Subjects	Main Results	Published Year
Tα1	269/317	▪The level of NLR increased ▪Patients with severe COVID-19 are not suitable for the treatment of glucocorticoid, immunoglobulin, thymosin, and ammonium glycyrrhizinate	2022 [76]
	306/1026	▪Tα1 use in COVID-19 was associated with poor clinical outcomes ▪Tα1 use at a later stage was significantly associated with a higher non-recovery rate than Tα1 use at an earlier stage ▪The duration to use Tα1 had a less significant effect on recovery rate	2021 [74]
	126/275	▪The use of Tα1 had no effect on promoting the recovery of CD4+ T cell and CD8+ T cell counts ▪The severity of the disease and use of Tα1 may actually be related to a prolonged time of virus clearance	2021 [71]
	232/1388	▪For non-severe patients with COVID-19, Tα1 can shorten viral RNA shedding duration and hospital stay but does not prevent the progression of COVID-19 and reduce the COVID-19-related mortality rate	2021 [68]
	27/47	▪The reduction rate of complement C3 level and C-reactive protein level was higher than that of the control group (p = 0.01, 0.04), but it has no obvious positive effect on virus elimination ▪Continuous monitoring of complement C3 levels and nucleic acid load are helpful for early assessment of discharge indications ▪The immune system is closely related to the severity of COVID-19 and clinical outcomes	2021 [77]
	327/771	▪The treatment of Tα1 was not associated with a difference in 28-day mortality in patients with COVID-19 after adjustment for baseline confounders ▪Subgroup analysis and phenotype analysis did not show benefits in 28-day mortality with Tα1 therapy	2021 [75]
	78/127	▪The male patients in the treatment group showed higher CRP and IL-6 levels after treatment, but the PCT level decreased significantly ▪Gender differences may be a factor in sustaining the immunity respond of COVID-19 to Tα1	2020 [76]
	36/76	▪Tα1 supplement significantly reduce mortality of severe COVID-19 patients ▪COVID-19 patients with counts of CD8+ T cells or CD4+ T cells in circulation lower than 400/μL or 650/μL, respectively, gain more benefits from Tα1 ▪Tα1 reverses T cell exhaustion and recovers immune reconstitution through promoting thymus output during SARS-CoV-2 infection	2020 [70]
	102/334	▪Treatment with Tα1 can markedly decrease 28-day mortality and attenuate acute lung injury in critical-type COVID-19 patients	2020 [78]