Patients on
dialysis are at
risk of severe
course of SARS-CoV-2 infection.
Understanding the neutralizing activity and coverage of
SARS-CoV-2 variants of
vaccine-elicited
antibodies is required to guide prophylactic and
therapeutic COVID-19 interventions in this frail
population. By analyzing
plasma samples from 130
hemodialysis and 13
peritoneal dialysis patients after two doses of BNT162b2 or
mRNA-1273
vaccines, we found that 35% of the
patients had low-level or undetectable
IgG antibodies to
SARS-CoV-2 Spike (S).
Neutralizing antibodies against the
vaccine-matched
SARS-CoV-2 and
Delta variant were low or undetectable in 49% and 77% of
patients, respectively, and were further reduced against other emerging variants. The fraction of non-responding
patients was higher in
SARS-CoV-2-naive
hemodialysis patients immunized with BNT162b2 (66%) than those immunized with
mRNA-1273 (23%). The reduced neutralizing activity correlated with low
antibody avidity.
Patients followed up to 7 months after
vaccination showed a rapid decay of the
antibody response with an average 21- and 10-fold reduction of
neutralizing antibodies to
vaccine-matched
SARS-CoV-2 and
Delta variant, which increased the fraction of non-responders to 84% and 90%, respectively. These data indicate that
dialysis patients should be prioritized for additional
vaccination boosts. Nevertheless, their
antibody response to
SARS-CoV-2 must be continuously monitored to adopt the best prophylactic and
therapeutic strategy.