Kidney transplant recipients and dialysis patients constitute a risk group for severe COVID-19. They are highly advised to get vaccinated according to the current guidelines. However, data on antibody response, cell responses and protection from events, and factors that might alter this response after a routine full series of vaccination remain incomplete for these populations. The aim of this article was to analyze the antibody responses after a full series of mRNA-based SARS-CoV-2 vaccination in kidney transplantation and dialysis patients and to define the factors that alter seroconversion status in these populations. In this systematic review, 18 studies investigating the antibody response to full vaccination with two doses of COVID-19 mRNA vaccines in hemodialysis, peritoneal dialysis, and kidney transplant patients were included. Kidney transplant and dialysis patients have a lower seroconversion rate after mRNA-based SARS-CoV-2 vaccination than the healthy population: 27.2% for kidney transplantation, 88.5% for dialysis patients while all healthy control in these studies seroconverted. Moreover, anti-S antibody titers were lower in seroconverted kidney transplantation or dialysis patients than in healthy control in all studies that assessed this variable. Older age and dialysis vintage, immunosuppressive or chemotherapy treatment, and lower serum albumin, white blood cell, lymphocyte and hemoglobin counts were associated with lower/no antibody response to vaccination. Dialysis patients and kidney transplant recipients have lower seroconversion rates after a full series of mRNA-based SARS-CoV-2 vaccination than the general population. Several factors are associated with an altered antibody response. A third dose could be considered in this patient group.