Blunted humoral immune response to the fourth dose of BNT162b2 COVID-19 vaccine in patients undergoing hemodialysis

Effect of Homologous and Heterologous Booster in COVID-19 Vaccination

Background: COVID-19 became a global health crisis in early 2020, and the way out of the crisis was the rapid development of vaccines by Sinopharm, Pfizer, and Sputnik, among others, which played a crucial role in controlling the pandemic. Therefore, this study aims to investigate the long-term immune response by measuring the levels of anti-S1 IgG antibodies induced by homologous and heterologous vaccination regimens. Methods: We investigated the titer of the anti-S1 IgG antibody produced for the viral surface antigen 3, 6 months after the second dose, before the third dose, and 1, 3, and 6 months after the third dose. Results: Anti-S1 IgG antibody levels significantly increased three/six months after the second dose and following the booster in individuals without prior COVID-19 infection who received all three homologous vaccine doses. The group that initially responded poorly to Sinopharm showed a significant and sustained increase after receiving the Pfizer booster. Additionally, prior SARS-CoV-2 infection between primary and booster vaccination boosted anti-S1 antibody titers in all individuals, regardless of the vaccine used. The highest vaccine efficacy was observed during the primary vaccination period and declined over time, especially during the omicron-dominant period. Conclusions: The results suggest that while homologous and heterologous booster doses can significantly enhance anti-S1 IgG antibody levels, prior SARS-CoV-2 infection and the type of vaccine administered influence the duration and magnitude of the immune response.

SARS-CoV-2 spike protein antibody titers after the fourth dose of BNT162b2 vaccine among Japanese patients undergoing hemodialysis: a single-center study

Patients undergoing hemodialysis are particularly vulnerable to severe outcomes of SARS-CoV-2 infection, with mortality rates higher than that of the general population. Vaccination reduces the risk of adverse outcomes, with booster doses being particularly beneficial. However, limited data are available on the effectiveness of subsequent vaccinations or their effect on increasing antibody levels. This single-center study aimed to investigate changes in SARS-CoV-2 IgG antibody titers following the fourth vaccination among 28 patients undergoing hemodialysis. Blood tests were conducted at various intervals post-vaccination, with a focus on identifying factors associated with antibody levels. The IgG antibody levels rapidly increased by Day 7 post-vaccination, with a median time to peak of 11 days. Antibody titers tended to be higher in male patients than in female patients. This study sheds light on the immune response to the fourth vaccination in patients undergoing hemodialysis. As this study included a small sample size, with a short observation period, further research is warranted to comprehensively understand the effectiveness of vaccination and the benefits of additional doses of vaccine.

Cellular and humoral immune responses to COVID-19 booster vaccination in Japanese dialysis patients

BACKGROUND

Dialysis patients are susceptible to developing severe coronavirus disease 2019 (COVID-19) due to hypoimmunity. Antibody titers against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) after the primary vaccinations are lower in hemodialysis (HD) patients than in healthy individuals. This study aimed to evaluate the effect of a SARS-CoV-2 booster vaccination in HD and peritoneal dialysis (PD) patients based on antibody titers and cellular and humoral immunity.

METHODS

Participants of the control, HD, and PD groups were recruited from 12 facilities. SARS-CoV-2 antigen-specific cytokine and IgG-antibody levels were measured. Regulatory T cells and memory B cells were counted using flow cytometry at 6 months after primary vaccination with BNT162b2 and 3 weeks after the booster vaccination in HD and PD patients and compared with those of a control group.

RESULTS

Booster vaccination significantly enhanced the levels of antibodies, cytokines, and memory B cells in three groups. The HD group showed significantly higher levels of IgG-antibodies, IL-1β, IL-2, IL-4, IL-17, and memory B cells than those in the control group at 3 weeks after the booster dose. The PD group tended to show similar trends to HD patients but had similar levels of IgG-antibodies, cytokines, and memory B cells to the control group.

CONCLUSIONS

HD patients had significantly stronger cellular and humoral immune responses than the control 3 weeks after the booster dose. Our findings will help in developing better COVID-19 vaccination strategies for HD and PD patients.

Anti-SARS-CoV-2 Spike Antibody Response to the Fourth Dose of BNT162b2 mRNA COVID-19 Vaccine and Associated Factors in Japanese Hemodialysis Patients

Background

We assessed the anti-SARS-CoV-2 spike antibody response to four doses of BNT162b2 mRNA COVID-19 vaccine in Japanese hemodialysis patients and determined factors associated with the anti-SARS-CoV-2 spike antibody titer after the fourth dose.

Methods

Fifty-one patients were enrolled in this single-center, prospective, longitudinal study. Change in anti-SARS-CoV-2 spike antibody titers between after the second and fourth doses were evaluated. Multiple linear regression analysis was used to identify factors associated with the anti-SARS-CoV-2 spike antibody titer after the fourth dose.

Results

The anti-SARS-CoV-2 spike antibody titer was higher 4 weeks after the fourth dose compared with 4 weeks after the third dose (30,000 [interquartile range (IQR), 14,000-56,000] vs 18,000 [IQR, 11,000-32,500] AU/mL, p<0.001) and 4 weeks after the second dose (vs 2896 [IQR, 1110-4358] AU/mL, p<0.001). Hypoxia-inducible factor prolyl hydroxylase inhibitor use (standard coefficient [β]=0.217, p=0.011), and the log-anti-SARS-CoV-2 spike antibody titer 1 week before the fourth dose (β=0.810, p<0.001) were correlated with the log-anti-SARS-CoV-2 spike antibody titer 4 weeks after the fourth dose, whereas only the log-anti-SARS-CoV-2 spike antibody titer 1 week before the fourth dose (β=0.677, p<0.001) was correlated with the log-anti-SARS-CoV-2 spike antibody titer 12 weeks after the fourth dose.

Conclusion

Hypoxia-inducible factor prolyl hydroxylase inhibitor use and the anti-SARS-CoV-2 spike antibody titer before the fourth dose were associated with the anti-SARS-CoV-2 spike antibody titer after the fourth dose in Japanese hemodialysis patients.

Vaccination for Patients Receiving Dialysis

Vaccinating patients receiving dialysis may prevent morbidity and mortality in this vulnerable population. The National Forum of End-Stage Renal Disease Networks (the Forum) published a revised vaccination toolkit in 2021 to update evidence and recommendations on vaccination for patients receiving dialysis. Significant changes in the last 10 years include more data supporting the use of a high-dose influenza vaccine, the introduction of the Heplisav-B vaccine for hepatitis B, and changes in pneumococcal vaccines, including the approval of the PCV15 and PCV20 to replace the PCV13 and PPSV23 vaccines. Additional key items include the introduction of vaccines against severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19), and a new vaccine to prevent respiratory syncytial virus disease. Historically, influenza and pneumococcal vaccinations were routinely administered by dialysis facilities, and because of possible risks of hematogenous spread of hepatitis B, dialysis providers often have detailed hepatitis B vaccine protocols. In March 2021, COVID-19 vaccines were made available for dialysis facilities to administer, although with the end of the public health emergency, vaccine policies by dialysis facilities against COVID-19 remains uncertain. The respiratory syncytial virus vaccine was authorized in 2023, and how dialysis facilities will approach this vaccine also remains uncertain. This review summarizes the Forum's vaccination toolkit and discusses the role of the dialysis facility in vaccinating patients to reduce the risk of severe infections.

Serial SARS-CoV-2 Antibody Titers in Vaccinated Dialysis Patients: Prevalence of Unrecognized Infection and Duration of Seroresponse

Rationale & Objective

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections are likely underdiagnosed, but the degree of underdiagnosis among patients receiving maintenance dialysis is unknown. The durability of the immune response after the third vaccine dose in this population also remains uncertain. This descriptive study tracked antibody levels to (1) assess the rate of undiagnosed infections and (2) characterize seroresponse durability after the third dose.

Study Design

Retrospective observational study.

Setting & Participants

SARS-CoV-2-vaccinated patients receiving maintenance dialysis through a national dialysis provider. Immunoglobulin G spike antibodies [anti-spike immunoglobulin (Ig) G] titers were assessed monthly after vaccination.

Exposures

Two and 3 doses of SARS-CoV-2 vaccine.

Outcomes

Undiagnosed and diagnosed SARS-CoV-2 infections; anti-spike IgG titers over time.

Analytical Approach

Undiagnosed SARS-CoV-2 infections were identified as an increase in anti-spike IgG titer of ≥100 BAU/mL, not associated with receipt of vaccine or diagnosed SARS-CoV-2 infection (by polymerase chain reaction test or antigen test). In descriptive analyses, anti-spike IgG titers were followed over time.

Results

Among 2,703 patients without previous coronavirus disease 2019 (COVID-19) who received an initial 2-dose vaccine series, 271 had diagnosed SARS-CoV-2 infections (3.4 per 10,000 patient-days) and 129 had undiagnosed SARS-CoV-2 infections (1.6 per 10,000 patient-days). Among 1,894 patients without previous COVID-19 who received a third vaccine dose, 316 had diagnosed SARS-CoV-2 infections (7.0 per 10,000 patient-days) and 173 had undiagnosed SARS-CoV-2 infections (3.8 per 10,000 patient-days). In both cohorts, anti-spike IgG levels declined over time. Of the initial 2-dose cohort, 66% had a titer of ≥500 BAU/mL in the first month, with 24% maintaining a titer of ≥500 BAU/mL at 6 months. Of the third dose cohort, 95% had a titer of ≥500 BAU/mL in the first month after the third dose, with 77% maintaining a titer of ≥500 BAU/mL at 6 months.

Limitations

The assays used had upper limits.

Conclusions

Among patients receiving maintenance dialysis, about 1 in every 3 SARS-CoV-2 infections was undiagnosed. Given this population's vulnerability to COVID-19, ongoing infection control measures are needed. A 3-dose primary mRNA vaccine series optimizes seroresponse rate and durability.

Plain-Language Summary

Patients receiving maintenance dialysis have been particularly vulnerable to COVID-19. Using serially measured antibodies, we found that a substantial proportion (about one-third) of SARS-CoV-2 infections among this population had been missed, both among those who had completed a 2-dose vaccine series and among those who had received a third vaccine dose. Such missed infections likely had only mild or minimal symptoms, but this failure to recognize all infections is concerning. Furthermore, vaccines have been effective among patients receiving dialysis, but our study additionally shows that the immune response wanes over time, even after a third dose. There is therefore a role for ongoing vigilance against this highly transmissible infection.