Comparison of BNT162b2 and mRNA1273 vaccines in solid organ transplant recipients: Post-Hoc analysis of a Japanese national prospective study

The coronavirus disease-19 (COVID-19) vaccine efficacy and immunogenicity in the immunocompetent population are well established. However, in solid organ transplant (SOT) recipients, because of their use of immunosuppressive medication, the immunogenicity of these severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines remains suboptimal. Both BNT162b2 and mRNA1273 have been used for some time, but their immunogenicity has not been directly compared in this immunocompromised patient group. We performed a post-hoc analysis of a previous prospective cohort study. The inclusion criteria were adult SOT recipients with active grafts at least 1 month after SOT. After giving consent, participants chose to receive either BNT162b2 or mRNA1273 vaccine. Anti-spike-protein-S antibody against SARS-CoV-2 was measured. Propensity scores were calculated via logistic regression to transform the probability of having received either BNT162b2 or mRNA1273 vaccine, and a model was developed. We enrolled 623 SOT recipients. In the propensity score-matched analysis, 100 recipients were selected for BNT162b2 and 100 for mRNA1273. SARS-CoV-2 anti-spike protein antibody positivity with BNT162b2 versus mRNA1273 at 3 weeks after the first dose, 1 month after the second dose, 3 months after the second dose, and 6 months after the second dose were 10% versus 19% (P = .07), 51% versus 58% (P = .30), 74% versus 88% (P = .01), and 78% versus 87% (P = .13), respectively. We conducted a propensity score-matched comparison of BNT162b2 and mRNA1273 vaccines as the primary series of COVID-19 vaccines in SOT recipients. We found significantly better immunogenicity with the mRNA1273 vaccine than with BNT162b2.