Table 1.

Clinical studies evaluating the antibody response to a full course (two doses) of anti-SARS-CoV-2 vaccines in solid organ transplant recipients. Only reports that have been published in extenso in peer-reviewed scientific journals are cited.

Author	Organ	N. of patients	Median age (years)	Median transplant-to vaccination interval (months)	Vaccine type	Type of serological test employed———Days between the second vaccine dose and evaluation of the antibody response	Antibody response rate	Positive predictors of antibody response
Boyarsky et al. [3]	SOT	658	-	-	mRNA1273 BNT162b2	Euroimmun® Roche Elecsys® ——— 28 to 31	Overall: 54% LT: 32%	• Younger age • Liver transplantation • Longer time since transplantation • Immunosuppression without mycophenolate • mRNA1273 vaccine
Rabinowich et al. [4]	Liver	80	60	60	BNT162b2	Liason S1/S2 IgG® ——— 10 to 20	47.5%	• Younger age • Normal kidney function • Low dosage of steroids • Immunosuppression without mycophenolate
Peled et al. [5]	Heart	77	62	89	BNT162b2	IgG anti RBD (“in house” ELISA) ——— 21	57%	• Immunosuppression without mycophenolate
Shostak et al. [6]	Lung, heart	168	60.5	>12 in 90% of cases	BNT162b2	Abbott® ——— 14-21	18%	• Younger age • Immunosuppression without mycophenolate and/or mTOR
Grupper et al. [7]	Kidney	136	58.6	39.2	BNT162b2	Liason S1/S2 IgG® ——— 14-21	37.5%	• Younger age • Immunosuppression without mycophenolate and/or mTOR • Low dose of steroids

SOT: solid organ transplantations; LT: liver transplanted; S1/S2 IgG: immunoglobulin G antibodies against subunits S1 and S2 of the SARS-CoV-2 spike protein; IgG anti RBD: Immunoglobulin G antibodies against Receptor Binding Domain of the SARS-CoV-2 spike protein; ELISA: enzyme-linked immunosorbent assay; mTOR: mammalian target of rapamycin.