Comparison of antibody response to two different mRNA Covid-19 vaccines in patients on hemodialysis

In hemodialysis patients, coronavirus disease 2019 is associated with high morbidity and mortality. Aim of the study was to evaluate the antibody level against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in patients treated with two different mRNA-based vaccines, in a multicenter survey.

Since April 2020, in the 5 participating Centers, periodic screening of all patients with PCR testing has been performed every 2 weeks. The study included two cohorts of patients on maintenance hemodialysis treated with the BNT162b2 or with the mRNA-1273 Covid-19 vaccine. The tests for antibodies against the receptor-binding domain was performed by the anti-SARS-CoV-2 S enzyme immunoassay (Roche Elecsys).

Of the 398 included patients, 303 received the BNT162b2 and 95 the mRNA-1273 vaccine. In patients without previous infection, the median levels of anti-S antibodies were 297 U/mL and 1,032 U/mL for those treated with BNT162b2 or mRNA-1273, respectively (p < 0.001). In patients with previous infection, the median levels of SARS-CoV-2 anti-S antibodies were 7,516 U/mL and 17,495 U/mL for those treated with BNT162b2 or mRNA-1273, respectively (p = 0.005). The Charlson comorbidity index (CCI) was significantly associated with protective levels of anti-spike IgG, with 3.6% of low- or non-responders having a CCI of 2-4 versus 18.9% in those with a CCI of 8 or more. The adjusted OR of developing a sufficient antibody level between the two vaccines was 3.91 (p = 0.0766) in favor of mRNA-1273.

Both of the evaluated mRNA-based vaccines for SARS-CoV-2 showed good efficacy. Preliminary data may data suggest a  higher antibody response to the mRNA-1273 vaccine.