SARS-CoV-2 spike protein antibody titers 6 months after SARS-CoV-2 mRNA vaccination among patients undergoing hemodialysis in Japan

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.

Clinical Course and Factors Correlated with Severe Morbidity and Mortality in Patients with Coronavirus Disease 2019 Undergoing Maintenance Dialysis in Kanagawa, Japan

Objective Patients undergoing maintenance dialysis are at a higher risk of morbidity and mortality due to severe coronavirus disease 2019 (COVID-19) than the general population. However, longitudinal data regarding this subpopulation of patients are lacking. We therefore examined the prognosis of patients with COVID-19 undergoing maintenance dialysis between 2020 and 2023. In addition, we explored the factors correlated with COVID-19 severity, focusing on the transition thereof throughout the observational period. Methods The primary outcome was the progression to severe or fatal COVID-19. We evaluated the correlation between the primary outcome and baseline demographic and clinical characteristics of patients. Patients undergoing maintenance dialysis who were hospitalized for mild-to-moderate COVID-19 between February 2020 and April 2023 were enrolled at four institutions in Kanagawa, Japan. Results Of the 173 patients, 7 (4.0%) developed severe COVID-19, and 12 (6.9%) died. The severe/death cohort was significantly older, with a higher percentage of unvaccinated patients than the non-severe cohort (58.2% and 25.0%, respectively; p=0.016). Thymus and activation-regulated chemokine levels on admission were lower in the severe/death cohort than in the non-severe cohort, albeit not to a statistically significant degree (148±84 mg/dL and 342±657 pg/mL, respectively; p=0.082). A multivariate logistic regression analysis revealed that the odds ratio for severe morbidity or death was 0.23 (95% confidence interval: 0.07-0.75) for vaccinated patients. Conclusion In patients undergoing maintenance dialysis, the severity rate of COVID-19 is approximately 10%. Vaccination was correlated with a reduced risk of severe COVID-19.

Humoral and Cellular Response Induced by Primary Series and Booster Doses of mRNA Coronavirus Disease 2019 Vaccine in Patients with Cardiovascular Disease: A Longitudinal Study

Preexisting cardiovascular disease (CVD) is a pivotal risk factor for severe coronavirus disease 2019 (COVID-19). We investigated the longitudinal (over 1 year and 9 months) humoral and cellular responses to primary series and booster doses of mRNA COVID-19 vaccines in patients with CVD. Twenty-six patients with CVD who received monovalent mRNA COVID-19 vaccines were enrolled in this study. Peripheral blood samples were serially drawn nine times from each patient. IgG against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike receptor-binding domain (RBD) was measured using an enzyme-linked immunosorbent assay. The numbers of interferon-γ-releasing cells in response to SARS-CoV-2 peptides were measured using an enzyme-linked immunospot assay. The RBD-IgG titers increased 2 weeks after the primary series and booster vaccination and waned 6 months after vaccination. The S1-specific T cell responses in patients aged < 75 years were favorable before and after booster doses; however, the Omicron BA.1-specific T cell responses were poor. These results suggest that regular vaccination is useful to maintain long-term antibody levels and has implications for booster dose strategies in patients with CVD. Additional booster doses, including Omicron variant-adapted mRNA vaccines, may be recommended for patients with CVD, regardless of age.

Factors associated with IgG titers against SARS-CoV-2 spike protein after second vaccination in people living with HIV controlled with anti-retroviral therapy

OBJECTIVE

This study aimed to identify factors associated with the response to the SARS-CoV-2 vaccine in people living with HIV (PLWH).

METHODS

This study was conducted at the Jikei University School of Medicine, Tokyo, Japan. IgG antibodies against spike and nucleocapsid proteins were detected using Abbott SARS-CoV-2 IgG II Quant assays.

RESULTS

During the investigation period, 371 PLWH were enrolled in this study. PLWH with previous COVID-19 infection, untreated or poorly controlled HIV infection, and those whose blood samples were obtained within less than seven days after the second vaccination were excluded. A total of 310 PLWH controlled with anti-retroviral therapy were included in the final analysis. Multivariate analysis demonstrated that chronic kidney disease (CKD) (β = -0.353, p = 0.049) and the duration between the second vaccination and blood sampling (β = -0.005, p < 0.001) were associated with low spike protein IgG titers.

CONCLUSION

Even without hemodialysis or kidney transplant, CKD was associated with vaccine response in PLWH.

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

BACKGROUND

We aimed to investigate the impact of a fourth dose of BNT162b2 vaccine (Comirnaty®, Pfizer-BioNTech) on anti-SARS-CoV-2 (anti-S IgG) antibody titers in patients receiving hemodialysis (HD) and healthcare workers (HCWs).

METHODS

A multi-institutional retrospective study at five dialysis clinics in Japan was conducted using 238 HD patients and 58 HCW controls who received four doses of the BNT162b2 mRNA vaccine. Anti-S IgG titers were measured at 1, 3, and 6 months after the second dose, at 1 and 5/6 months after the third dose, and at 1 month after the fourth dose of vaccine.

RESULTS

The log anti-S IgG titers of the HD patients after the second vaccination were significantly lower than those of the control group, but equalized 1 month after the third vaccination: 9.94 (95% CI 9.82-10.10) vs. 9.81 (95% CI 9.66-9.96), (P = 0.32). In both groups, the fold-increase in anti-S IgG titers was significantly lower after the fourth dose than after the third dose of vaccine. In addition, there was a strong negative correlation between antibody titers 1 month after the fourth vaccination and antibody titers immediately before the vaccination. In both groups, the waning rate of anti-S IgG titers from the post-vaccination peak level after the third vaccine dose was significantly slower than that after the second dose.

CONCLUSIONS

These findings suggest that the humoral immune response was blunted after the fourth dose of the conventional BNT162b2 vaccine. However, multiple vaccinations could extend the window of humoral immune protection.

Humoral response after BNT162b2 vaccine in Japanese hemodialysis patients

Background

Hemodialysis patients are more likely to be severely affected if infected by COVID-19. Contributing factors include chronic kidney disease, old age, hypertension, type 2 diabetes, heart disease, and cerebrovascular disease. Therefore, action against COVID-19 for hemodialysis patients is an urgent issue. Vaccines are effective in preventing COVID 19 infection. In hemodialysis patients, however, responses to hepatitis B and influenza vaccines are reportedly weak. The BNT162b2 vaccine has shown an efficacy rate of about 95% in the general population, but as far as we know there are only several reports of efficacy data in hemodialysis patients in Japan.

Methods

We assessed serum anti-SARS-CoV-2 IgG antibody (Abbott SARS-CoV-2 IgG II Quan) in 185 hemodialysis patients and 109 health care workers. The exclusion criterion was positivity for SARS-CoV-2 IgG antibody before vaccination. Adverse reactions to BNT162b2 vaccine were evaluated through interviews.

Results

Following vaccination, 97.6% of the hemodialysis group and 100% of the control group were positive for the anti-spike antibody. The median level of anti-spike antibody was 2,728.7 AU/mL (IQR, 1,024.2-7,688.2 AU/mL) in the hemodialysis group and 10,500 AU/ml (IQR, 9,346.1-2,4500 AU/mL) in the health care workers group. The factors involved in the low response to the BNT152b2 vaccine included old age, low BMI, low Cr index, low nPCR, low GNRI, low lymphocyte count, steroid administration, and complications related to blood disorders.

Conclusions

Humoral responses to BNT162b2 vaccine in hemodialysis patients are weaker than in a healthy control sample. Booster vaccination is necessary for hemodialysis patients, especially those showing a weak or non-response to the two-dose BNT162b2 vaccine.Trial registration UMIN, UMIN000047032. Registered 28 February 2022, https://center6.umin.ac.jp/cgi-bin/ctr/ctr_reg_rec.cgi.