Factors associated with anti-SARS-CoV-2 spike antibody titers after a second BNT162b2 mRNA COVID-19 vaccination in Japanese hemodialysis 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.

Antibody Response to SARS-CoV-2 Vaccination in Patients with End-Stage Kidney Disease on Hemodialysis

Patients with end-stage kidney disease on hemodialysis (ESKD-HD) have a high risk of contracting severe COVID-19. Vaccination can help reduce disease severity, but the immune dysregulation observed in these patients may result in an inadequate antibody response. Therefore, we aimed to evaluate the immune response postvaccination in ESKD-HD patients. This prospective cohort study was conducted in two hemodialysis centers in Indonesia. We enrolled ESKD-HD patients (n = 143) pre- and postvaccination and compared them to healthy subjects (n = 67). SARS-CoV-2 antibody response was assessed using anti-S-RBD antibodies and SVNT % inhibition tests. We performed bivariate and multivariate analysis to determine factors associated with SARS-CoV-2 antibody levels. Seropositive conversion was observed in 97% ESKD-HD subjects postvaccination. Compared with healthy subjects, ESKD-HD patients showed a comparable anti-S-RBD antibody titer postvaccination. mRNA vaccines remained a significant factor for the high immune response, while hypoalbuminemia correlated with lower immune response. In conclusion, ESKD-HD patients showed a robust immune response postvaccination. mRNA vaccines induced a stronger antibody response than other vaccines. Lower levels of serum albumin correlate with lower immune responses in ESKD-HD patients after vaccination.

Lack of Evidence on Association between Iron Deficiency and COVID-19 Vaccine-Induced Neutralizing Humoral Immunity

Iron is a crucial micronutrient for immunity induction in response to infections and vaccinations. This study aimed to investigate the effect of iron deficiency on COVID-19-vaccine-induced humoral immunity. We investigated the effectiveness of COVID-19 vaccines (BNT162b2, mRNA-1273, and ChAdOx nCov-2019) in iron-deficient individuals (n = 63) and provide a side-by-side comparison to healthy controls (n = 67). The presence of anti-SARS-CoV-2 spike (S) and anti-nucleocapsid (NP) IgG were assessed using in-house S- and NP-based ELISA followed by serum neutralization test (SNT). High concordance between S-based ELISA and SNT results was observed. The prevalence of neutralizing antibodies was 95.24% (60/63) in the study group and 95.52% (64/67) in the controls with no significant difference. The presence/absence of past infection, period since vaccination, vaccine type, and being iron-deficient or having iron-deficiency anemia did not exert any significant effect on the prevalence or titer of anti-SARS-CoV-2 neutralizing antibodies. NP-based ELISA identified individuals unaware of exposure to SARS-CoV-2. Moreover, absence of anti-NP IgG was noted in participants who were previously diagnosed with COVID-19 suggesting the unpredictability of after-infection immunity. To sum up, this study demonstrated an initial lack of evidence on the association between iron deficiency and the effectiveness of COVID-19-vaccine-induced neutralizing humoral immunity. Similar studies with larger sample size remain necessary to obtain comprehensive conclusions about the effect or lack of effect of iron on COVID-19-vaccine effectiveness.

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.