Table 1.

Summary of clinical studies assessing the immune response to mRNA vaccinations in the setting of solid organ transplantation.

Publication	Study population	Vaccine, dose	Outcome	Results, comments
Boyarsky et al⁹	658 SOT recipients	Pfizer-BioNTech and Moderna, one dose	^aAntibody response	357/658 (54%) with detectable IgG at median 29 days after Dose 2. Older age, use of mycophenolate, use of Pfizer BioNTech vaccine and time since transplant was associated with negative serology.
Yi et al¹⁰	145 KT recipients	Pfizer-BioNTech and Moderna, one dose	Antibody response (unknown test)	8/145 (5.5%) with anti-spike IgG measured prior to Dose 2. No additional data re: timing from vaccine dose, risk factors.
Benotmane et al¹¹	242 KT recipients	Moderna, one dose	^aAntibody response	26/242 (10.7%) with detectable anti-spike IgG at 28 days from Dose 1. Shorter time from transplant and use of anti-thymocyte globulin, mycophenolate and steroids associated with negative serology by univariate analysis.
Grupper et al.¹³	136 KT recipients	Pfizer BioNTech, two doses	Antibody response	51/136 (37.5%) with detectable IgG at median 16 days after Dose 2. Negative serology associated with increasing age, pre-transplant dialysis duration, living donor, high dose steroids in previous 12 months, mycophenolate, triple immunosuppression, low lymphocyte count, higher serum creatinine and lower GFR by univariate analysis
Sattler et al¹²	39 KT recipients	Pfizer BioNTech, two doses	^aAntibody and T-cell response	1/39 (2.6%) had IgG seroconversion at 8 days following Dose 2. Prevalence of spike specific CD4 cells was similar to controls 36/39 (92%), spike specific CD8 cell response only noted in 2/29 (5.13%)No alloreactivity noted.
Peled et al¹⁴	77 HT recipients	Pfizer BioNTech, two doses	^aAntibody response	14/77 (18%) with detectable RBD IgG at mean 21 days following Dose 2. Mycophenolate use associated with lower odds of seroconversion in multivariate analysis. No serious adverse events noted by 41 days from Dose 2.
Havlin et al¹⁵	48 LT recipients	Pfizer BioNTech, two doses	^aAntibody and T-cell response	0/30 patients had detectable RBD IgG at one week following Dose 2 and 0/21 at 4-6 weeks following Dose 2. SARS-CoV-2 specific T-cells noted in 4/12 (33.3%) 9 weeks after Dose 2. Mycophenolate use associated with lack of IgG in univariate analysis.

SOT is solid organ transplant, KT is kidney transplant, HT is heart transplant, LT is lung transplant.

Antibody testing for SARS-CoV-2 anti-spike IgG was performed by the following tests: Boyarsky et al - anti-SARS-CoV-2 Spike S1 IgG ELISA (Euroimmun, Lubeck, Germany). Some samples tested using the SARS-CoV-2 S enzyme immunoassay (Roche Elecsys) that tests for antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein.

Yi et al – not mentioned in paper.

Benotmane et al - ARCHITECT IgG II Quant test (Abbott, Abbott Park, IL). Titer > 50 arbitrary units (AUs)/ml considered positive.

Grupper et al - LIAISON SARS-CoV-2 S1/S2 IgG chemiluminescent assay (DiaSorin S.p.A., Saluggia, Italy) used to detect IgG antibodies directed against a recombinant S protein (S1/S2). Titers ≥15 AU/mL considered positive.

Sattler et al – Anti-SARS-CoV2 spike S1 domain-specific IgG ELISA (Euroimmun, Lübeck, Germany). OD ratios of ≥1.1 considered positive.

Peled et al - In-house ELISA that detects IgG against SARS-CoV-2 RBD.

Havlin et al - anti-SARS-CoV-2 Spike S1 IgG ELISA (Euroimmun, Lubeck, Germany) and confirmed independently by Microblot-Array COVID-19 IgG against a mix of recombinant antigens (TestLine Clinical Diagnostics, Brno, Czech Republic) and chemiluminiscent immunoassay (CLIA) Liaison SARS-CoV-2 Trimeric S IgG against the trimeric spike S1 protein (Diasorin, Saluggia, Italy).