Humoral Immune Response of the Additional Chadox1 NCOV-19 Vaccine Following a Two-Dose Inactivated Whole-Virus SARS-COV-2 Vaccination in Patients on Dialysis

BACKGROUND AND AIMS Patients with end-stage kidney disease (ESKD) are at risk of coronavirus disease 2019 infection and its associated complications. A previous study demonstrated that patients with ESKD on dialysis generated suboptimal humoral immune response (HIR) and lower seroconversion rate after two-dose inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination as compared to healthy individuals. In this study, we examined HIR of the additional dose of ChAdOx1 nCoV-19 vaccine following a standard two-dose inactivated whole-virus SARS-CoV-2 vaccination in patients on dialysis, and compared to those of healthy controls. METHOD We recruited 59 patients with ESKD [31 patients on haemodialysis (HD) and 28 on peritoneal dialysis (PD)) and 16 healthy controls who received two doses of inactivated SARS-CoV-2 vaccine (V2) from Ramathibodi hospital and Banphaeo General Hospital, Bangkok, Thailand, from July 2021 to September 2021. All participants were administered a third dose of the ChAdOx1nCoV-19 vaccine (V3) with a 6-week interval between the V2 to V3. HIR was measured 2 weeks after V2 and V3 using SARS-CoV-2 immunoglobulin G (IgG) assay, which detects antibodies against the S1 receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Median anti-RBD IgG titer and seroconversion rate, defined as anti-RBD IgG titre ≥ 7.1 BAU/mL, were compared among ESKD patients and to those of healthy controls using the Kruskal–Wallis H test and the chi-squared test, respectively. RESULTS Baseline characteristics of patients on HD, PD and healthy controls are shown in Table 1. Demographic characteristics and baseline laboratory parameters were comparable between the HD and PD groups, except for a lower mean serum albumin level in the PD group (P < .001). None of the healthy controls were immunocompromised or receiving immunosuppressive therapies.Table 1.Clinical characteristics, n (%) HD (n = 31)PD (n = 28)Controls (n = 16)Age, years45 (10)41 (12)41 (9)Male, n (%) 23 (74)17 (61)5 (31)Body mass index, kg/m226 (5)24 (4)27 (6)Charlson Comorbidity Index, median (IQR) 3 (3–5)2.5 (2–4)0Comorbidities, n (%)  Diabetes mellitus HypertensionCardiovascular disease 14 (45)24 (77)7 (23)7 (25)25 (89)2 (7)1 (6)2 (13)0 Causes of ESKD, n (%) Diabetic nephropathy Hypertensive nephropathy Others Unknown6 (19)3 (10)5 (16)14 (45)5 (18)8 (29)8 (29)7 (25)NADialysis vintage, months, median (IQR)33 (17–84)34 (7–57)NATotal Kt/Vurea1.6 (0.3)2.0 (0.4)NALaboratories White blood cells, × 109/L Absolute lymphocyte count, × 109/L Haemoglobin, g/dL Ferritin, ng/mL, median (IQR) Albumin, g/L6.9 (1.9)1.6 (0.5)11 (2)301 (119–441)40 (4)7.3 (2.8)1.5 (0.8)10 (2)367 (156–751)33 (4)*7.7 (2.4)2.2 (0.9)NANANA *P < .05. At 2 weeks after V3, the median anti-RBD IgG titres were significantly increased in all groups compared to those levels after V2 (85[33–412] versus 1566 [861–3083] BAU/mL for patients on HD, 81 [15–144] versus 913 [293–1359] BAU/mL for patients on PD and 250 [92–603] versus 2210 [1531–2782] BAU/mL for healthy controls;P < .001 for all groups). Comparing antibody levels between groups after V3, patients on PD generated significantly lower anti-RBD IgG titer than patients on HD (P = .02) and healthy controls (P < .01) (Figure 1A). The seroconversion rate of the HD and PD groups improved from 94% and 82% after V2 to 100% after V3 in both groups (P = .16 and P = .03, respectively) (Figure 1B). All patients on dialysis who had anti-RBD IgG < 7.1 BAU/mL after V2 (7/59 patients) seroconverted after the additional dose of ChAdOx1 nCoV-19 vaccine. CONCLUSION We suggest that an additional ChAdOx1 nCoV-19 vaccine after a primary two doses inactivated SARS-CoV-2 vaccination could improve seroconversion rate and magnitude of humoral immune response in patients on dialysis. The durability of the immune response to this vaccination regimen requires further study.

An additional dose of viral vector COVID-19 vaccine and mRNA COVID-19 vaccine in kidney transplant recipients: A randomized controlled trial (CVIM 4 study).

Immunogenicity following an additional dose of Coronavirus disease 2019 (COVID-19) vaccine was investigated in an extended primary series among kidney transplant (KT) recipients. Eighty-five KT participants were randomized to receive either an mRNA (M group; n = 43) or viral vector (V group; n = 42) vaccine. Among them, 62% were male, with a median (IQR) age of 50 (43-59) years and post-transplantation duration of 46 (26-82) months. At 2 weeks post-additional dose, there was no difference in the seroconversion rate between the M and V groups (70% vs. 65%, p = .63). A median (IQR) of anti-RBD antibody level was not statistically different between the M group compared with the V group (51.8 [5.1-591] vs. 28.5 [2.9-119.3] BAU/ml, p = .18). Furthermore, the percentage of participants with positive SARS-CoV-2 surrogate virus neutralization test results was not statistically different between groups (20% vs. 15%, p = .40). S1-specific T cell and RBD-specific B cell responses were also comparable between the M and V groups (230 [41-420] vs. 268 [118-510], p = .65 and 2 [0-10] vs. 2 [0-13] spot-forming units/106 peripheral blood mononuclear cells, p = .60). In conclusion, compared with an additional dose of viral vector COVID-19 vaccine, a dose of mRNA COVID-19 vaccine did not elicit significantly different responses in KT recipients, regarding either humoral or cell-mediated immunity. (TCTR20211102003).

Durability of Humoral and Cellular Immunity after an Extended Primary Series with Heterologous Inactivated SARS-CoV-2 Prime-Boost and ChAdOx1 nCoV-19 in Dialysis Patients (ICON3).

The durability of a three-dose extended primary series of COVID-9 vaccine in dialysis patients remains unknown. Here, we assessed dynamic changes in SARS-CoV-2-specific humoral and cell-mediated immunity at baseline, 3 months, and 6 months after the extended primary series in 29 hemodialyzed (HD), 28 peritoneal dialyzed (PD) patients, and 14 healthy controls. Participants received two doses of inactivated SARS-CoV-2 vaccine followed by a dose of ChAdOx1 nCoV-19 vaccine. At 6 months, median anti-RBD IgG titers (IQR) significantly declined from baseline in the HD (1741 (1136-3083) BAU/mL vs. 373 (188-607) BAU/mL) and PD (1093 (617-1911) BAU/mL vs. 180 (126-320) BAU/mL) groups, as did the mean percent inhibition of neutralizing antibodies (HD: 96% vs. 81%; PD: 95% vs. 73%) (all p < 0.01). Age and post-vaccination serological response intensity were predictors of early humoral seroprotection loss. In contrast, cell-mediated immunity remained unchanged. In conclusion, humoral immunity declined substantially in dialysis patients, while cell-mediated immunity remained stable 6 months after the extended heterologous primary series of two inactivated SARS-CoV-2/ChAdOx1 nCoV-19 vaccine. A booster dose could be considered in dialysis patients 3 months after this unique regimen, particularly in the elderly or those with a modest initial humoral response.

Detectable Duration of Viable SARS-CoV-2, Total and Subgenomic SARS-CoV-2 RNA in Noncritically Ill COVID-19 Patients: a Prospective Cohort Study.

Determination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity is important in guiding the infection control and differentiating between reinfection and persistent viral RNA. Although viral culture is the gold standard to determine viral infectivity, the method is not practical. We studied the kinetics of SARS-CoV-2 total RNAs and subgenomic RNAs (sgRNAs) and their potential role as surrogate markers of viral infectivity. The kinetics of SARS-CoV-2 sgRNAs compared to those of the culture and total RNA shedding in a prospective cohort of patients diagnosed with coronavirus disease 2019 (COVID-19) were investigated. A total of 260 nasopharyngeal swabs from 36 patients were collected every other day after entering the study until the day of viral total RNA clearance, as measured by reverse transcription PCR (RT-PCR). Time to cessation of viral shedding was in order from shortest to longest: by viral culture, sgRNA RT-PCR, and total RNA RT-PCR. The median time (interquartile range) to negativity of viral culture, subgenomic N transcript, and N gene were 7 (5 to 9), 11 (9 to 16), and 18 (13 to 21) days, respectively (P < 0.001). Further analysis identified the receipt of steroid as the factors associated with longer duration of viral infectivity (hazard ratio, 3.28; 95% confidence interval, 1.02 to 10.61; P = 0.047). We propose the potential role of the detection of SARS-CoV-2 subgenomic RNA as the surrogate marker of viral infectivity. Patients with negative subgenomic N RNA RT-PCR could be considered for ending isolation. IMPORTANCE Our study, combined with existing evidence, suggests the feasibility of the use of subgenomic RNA RT-PCR as a surrogate marker for SARS-CoV-2 infectivity. The kinetics of SARS-CoV-2 subgenomic RNA should be further investigated in immunocompromised patients.

Immunogenicity of ChAdOx1 nCoV-19 vaccine after a two-dose inactivated SARS-CoV-2 vaccination of dialysis patients and kidney transplant recipients.

Vaccination with inactivated SARS-CoV-2 virus produces suboptimal immune responses among kidney transplant (KT), peritoneal dialyzed (PD), and hemodialyzed (HD) patients. Participants were vaccinated with two-dose inactivated SARS-CoV-2 vaccine (V2) and a third dose of ChAdOx1 nCoV-19 vaccine (V3) at 1-2 months after V2. We enrolled 106 participants: 31 KT, 28 PD, and 31 HD patients and 16 controls. Among KT, PD, and HD groups, median (IQR) of anti-receptor binding domain antibody levels were 1.0 (0.4-26.8), 1092.5 (606.9-1927.2), and 1740.9 (1106-3762.3) BAU/mL, and percent neutralization was 0.9 (0-9.9), 98.8 (95.9-99.5), and 99.4 (98.8-99.7), respectively, at two weeks after V3. Both parameters were significantly increased from V2 across all groups (p < 0.05). Seroconversion and neutralization positivity rates in PD, HD, and control groups were 100% but were impaired in KT patients (39% and 16%, respectively). S1-specific T-cell counts were increased in PD and HD groups (p < 0.05) but not in KT patients. The positive S1-specific T-cell responder rate was > 90% in PD, HD, and control groups, which was higher than that in KT recipients (74%, p < 0.05). The heterologous inactivated virus/ChAdOx1 nCoV-19 vaccination strategy elicited greater immunogenicity among dialysis patients; however, inadequate responses remained among KT recipients (TCTR20210226002).

SARS-CoV-2-specific humoral and cell-mediated immune responses after immunization with inactivated COVID-19 vaccine in kidney transplant recipients (CVIM 1 study).

Immunogenicity following inactivated SARS-CoV-2 vaccination among solid organ transplant recipients has not been assessed. Seventy-five patients (37 kidney transplant [KT] recipients and 38 healthy controls) received two doses, at 4-week intervals, of an inactivated whole-virus SARS-CoV-2 vaccine. SARS-CoV-2-specific humoral (HMI) and cell-mediated immunity (CMI) were measured before, 4 weeks post-first dose, and 2 weeks post-second dose. The median (IQR) age of KT recipients was 50 (42-54) years and 89% were receiving calcineurin inhibitors/mycophenolate/corticosteroid regimens. The median (IQR) time since transplant was 4.5 (2-9.5) years. Among 35 KT patients, the median (IQR) of anti-RBD IgG level measured by CLIA after vaccination was not different from baseline, but was significantly lower than in controls (2.4 [1.1-3.7] vs. 1742.0 [747.7-3783.0] AU/ml, p < .01) as well as percentages of neutralizing antibody inhibition measured by surrogate viral neutralization test (0 [0-0] vs. 71.2 [56.8-92.2]%, p < .01). However, the median (IQR) of SARS-CoV-2 mixed peptides-specific T cell responses measured by ELISpot was significantly increased compared with baseline (30 [4-120] vs. 12 [0-56] T cells/106  PBMCs, p = .02) and not different from the controls. Our findings revealed weak HMI but comparable CMI responses in fully vaccinated KT recipients receiving inactivated SARS-CoV-2 vaccination compared to immunocompetent individuals (Thai Clinical Trials Registry, TCTR20210226002).

Short-Term Immunogenicity Profiles and Predictors for Suboptimal Immune Responses in Patients with End-Stage Kidney Disease Immunized with Inactivated SARS-CoV-2 Vaccine.

INTRODUCTION: Patients with end-stage kidney disease (ESKD) are at risk of severe coronavirus disease and mortality. Immunogenicity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivated whole-virus vaccine in patients with ESKD has never been explored. METHODS: We conducted a prospective cohort study of 60 patients with ESKD and 30 healthy controls. All participants received two doses of an inactivated whole-virus SARS-CoV-2 vaccine (Sinovac Biotech Ltd) 4 weeks apart. SARS-CoV-2-specific humoral and cell-mediated immune responses were investigated and referenced with healthy controls. RESULTS: After two doses, an anti-receptor-binding domain immunoglobulin G of 50 AU/ml or greater was present in 53 of 60 patients (88%) in the ESKD group and all participants (100%) in the control group (P = 0.05). The percentage of patients with ESKD and controls with neutralizing antibodies of 35% threshold or greater was 58% and 88%, respectively (P = 0.01). Furthermore, the proportion of patients with ESKD and S1-specific T cell response was comparable with controls (82% vs. 77%, P = 0.45). Old age, high ferritin level, and low absolute lymphocyte count were independently associated with poor humoral immune responses. CONCLUSIONS: Patients with ESKD could develop similar SARS-CoV-2-specific cell-mediated immune responses compared to healthy controls, although suboptimal humoral immune responses were observed following two doses of SARS-CoV-2 vaccination. Therefore, patients with ESKD and the abovementioned factors are at risk of generating inadequate humoral immune responses, and a vaccine strategy to elicit greater immunogenicity among these relatively immunocompromised patients is warranted. (Thai Clinical Trials Registry, TCTR20210226002).

The COVID-19 Pandemic: What We Have Learned from Thai Experiences

This article summarizes and shares experiences of how Thailand has managed and controlled the coronavirus disease 2019 (COVID-19) outbreaks. COVID-19, an emerging severe respiratory infection caused by severe acute respiratory syndrome coronavirus 2 (SiRS-CoV-2), has posed an unprecedented, serious health threat to humankind. Advancements in health science enables us to recognize the syndrome and its etiology rapidly. The ability to transmit the virus before the development of symptoms makes control efforts a difficult task. However, primary preventive practices, i.e., physical/social distancing, wearing masks, hand hygiene, early detection of disease and isolation of patients, can slow down the epidemic in many countries, including Thailand. Delaying interventions could worsen the situation, but this is not the case with Thailand. It has actively deployed necessary preventive measures since the early phase of the pandemic with government leadership;the healthcare system's infrastructure has had strong public engagement and collaboration of all sectors in the country. Although there have been worrisome outbreaks, Thailand finally succeeded in controlling the epidemic within a few months using simple science-based recommendations. Shutting down economic and social activities placed a financial burden on all sectors. Yet, formal and informal supports for those with financial constraints, donations to the healthcare sectors, and innovation of safety devices emerged everywhere. In the time of crisis, there are hopes and innovations. Science, collaboration, united policies, and standard practice are universal measures for humankind to survive the challenges of threats that continuously emerge. Finally, we should always be alert and ready to deploy intensive preventive measures against new waves of epidemic promptly because it is likely that this pandemic will not end soon.