ABSTRACT
BACKGROUND: Since December 2019, kidney transplant recipients (KTRs) have experienced a great impact of the coronavirus disease 2019 (COVID-19) pandemic, with a higher risk of morbidity and mortality compared to the general population. Preliminary data in KTRs suggest that the Omicron variant, which has been dominant since December 2021, is more infectious than the previous ones but is associated with reduced risk of severity and low lethality rates. The purpose of our study was to assess the disease course and outcomes of the SARS-CoV-2 infection in KTRs during the Omicron-surge. METHODS: This retrospective study included 451 KTRs diagnosed with SARS-CoV-2 infection between 1 December 2021 and 30 September 2022. Demographic and clinical characteristics at the time of infection, vaccination data, treatment, clinical course, and outcomes were recorded and analyzed. RESULTS: Mean age was 51.8 ± 13.7 years with a male predominance (61.2%). The majority (76.1%) were vaccinated with at least three doses of the available mRNA vaccines, although serology revealed low anti-SARS-CoV-2 antibody titers before infection (33 [3.3-1205] AU/mL). Only 6% of the patients experienced moderate-severe disease. Accordingly, there was low prevalence of adverse outcomes, such as SARS-CoV-2-related hospitalization (11.3%) and death (0.9%). Multivariate analysis revealed that only age significantly increased the risk of SARS-CoV-2-related hospitalization. CONCLUSIONS: During the Omicron wave, the clinical course of the SARS-CoV-2 infection in KTRs has substantially changed, with lower rates of moderate and severe disease and a low prevalence of adverse outcomes. Prospective clinical trials are warranted to further elucidate the evolving pathogenesis, management, and long-term outcomes of COVID-19 in such high-risk populations.
ABSTRACT
Chronic kidney disease patients, especially those on hemodialysis, are at the highest risk of a severe course and death from COVID-19. Moreover, they appear to have suboptimal response in both cellular and humoral immunity after vaccination. The present study investigated humoral and cellular response and safety after two doses of either of the two authorized mRNA vaccines in a cohort of 310 patients on maintenance dialysis. The antibody response rate was 94.5%, with a median (25th, 75th) antibody titer of 3478 (1236, 8141) AU/mL. Only mild adverse effects were observed. Only vaccine type was independently associated with immunogenicity. Α statistically significant difference in favor of mRNA1273 versus BNT162b2 vaccine was observed. Antibody positivity (100% vs. 94.3%, p < 0.001), median (25th, 75th) antibody levels: 9499 (6118, 20,780) AU/mL vs. 3269 (1220, 7807) AU/mL (p < 0.001). Among the 65 patients tested for T-cell response, 27 (41.5%) had a positive one with a median (25th, 75th) antibody titer of 6007 (3405, 12,068) AU/mL, while 38 with no T-cell response presented a lower median (25th, 75th) antibody titer of 1744 (850, 4176) AU/mL (p < 0.001). Both mRNA vaccines are safe for dialysis patients and can trigger humoral and cellular responses, although with lower titers than those that have been reported to healthy individuals.
ABSTRACT
Due to their higher risk of developing life-threatening COVID-19 disease, solid organ transplant (SOT) recipients have been prioritized in the vaccination programs of many countries. However, there is increasing evidence of reduced immunogenicity to SARS-CοV-2 vaccination. The present study investigated humoral response, safety, and effectiveness after the two mRNA vaccines in 455 SOT recipients. Overall, the antibody response rate was low, at 39.6%. Higher immunogenicity was detected among individuals vaccinated with the mRNA1273 compared to those with the BNT162b2 vaccine (47% vs. 36%, respectively, p = 0.025) as well as higher median antibody levels of 31 (7, 372) (AU/mL) vs. 11 (7, 215) AU/mL, respectively. Among the covariates assessed, vaccination with the BNT162b2 vaccine, antimetabolite- and steroid-containing immunosuppression, female gender, the type of transplanted organ and older age were factors that negatively influenced immune response. Only mild adverse effects were observed. Our findings confirm poor immunogenicity after vaccination, implicating a reevaluation of vaccination policy in SOT recipients.
ABSTRACT
The present study presents the clinical outcome of SARS-CoV-2 disease in relation to the humoral response in fully vaccinated solid organ transplant (SOT) recipients. Our patient cohort consists of 455 SOT recipients, vaccinated with one of the 2 approved mRNA vaccines. The antibody response was measured 1 month after the second dose, and previously infected patients have been excluded. Of the 449 remaining patients, 15 (3.34%) tested positive, using SARS-CoV-2 polymerase chain reaction. Their mean age was 43.7 ±14.4 years, and median time from transplantation was 7.8 years (1.2-30.2). Eleven patients (73.3%) had been vaccinated with BNT162b2 and 4 (26.7%) with the mRNA1273 vaccine. At the time of infection 9 (60%) patients had a negative (<50 AU/mL) antibody titer, and 6 (40%) had a positive one (>50 AU/mL). Median antibody titer, 27.4± 14.0 days after the second dose, measured at 13 AU/mL (0-7480 AU/mL). Renal function did not appear to be affected by the disease. Τhe mean estimated glomerular filtration rate at diagnosis was 48 ± 15 mL/min, and when in a 29-day (1-101) median follow-up was 53.9± 20.9 mL/min. Of the 15 patients, 7 had mild symptoms and were not hospitalized, and of the remaining 8 (53.3%) who needed hospitalization 7 had severe disease and 2 of them expired. The study confirms the variable and often severe course of coronavirus 2019 infection in SOT recipients, even after their full vaccination, highlighting the need to vaccinate their close relatives and to accelerate the implementation of the booster dose of vaccine.