Impact of tozinameran (BNT162b2) mRNA vaccine on kidney transplant and chronic dialysis patients: 3-5 months follow-up

18-month longitudinal SARS COV-2 neutralizing antibody dynamics in haemodialysis patients receiving heterologous 3-dose vaccination (AZD-1222- AZD-1222- BNT162b2) in a lower middle income setting

BACKGROUND

Patients with chronic kidney disease on haemodialysis (HD) were given priority COVID-19 vaccination due to increased disease risk. The immune response to COVID-19 vaccination in patients on HD was diminished compared to healthy individuals in 2-dose studies. This study aimed to evaluate seroconversion rate, neutralizing antibody (nAB) levels and longitudinal antibody dynamics to 3-dose heterologous vaccination against COVID-19 in a cohort of HD patients compared to healthy controls and assess patient factors associated with antibody levels.

METHODS

This study was a case-control longitudinal evaluation of nAB dynamics in 74 HD patients compared to 37 healthy controls in a low/middle income setting. Corresponding samples were obtained from the two cohorts at time-points (TP) 1-1-month post 2nd dose of AZD1222 vaccine, TP2- 4 months post 2nd dose, TP4- 2 weeks post 3rd dose with BNT162b2 vaccine, TP5-5 months post 3rd dose and TP6-12 months post 3rd dose. Additional data is available at TP0- pre 2nd dose and TP3- 6 months post 2nd dose in HC and HD cohorts respectively. Anti-SARS-CoV-2 nAB were detected using Genscript cPassTM pseudoviral neutralization kit. Demographic and clinical details were obtained using an interviewer administered questionnaire.

RESULTS

Cohorts were gender matched while mean age of the HD cohort was 54.1yrs (vs HCs mean age, 42.6yrs, p < 0.05). Percentage seroconverted and mean/median antibody level (MAB) in the HD cohort vs HCs at each sampling point were, TP1-83.7% vs 100% (p < 0.05), MAB-450 IU/ml vs 1940 IU/ml (p < 0.0001); TP2-71.4% vs 100%, (p < 0.001), MAB- 235 IU/ml vs 453 IU/ml, (p < 0.05); TP4-95.2% vs 100% (p > 0.05), MAB-1029 IU/ml vs 1538 IU/ml (p < 0.0001); TP5-100% vs 100%, MAB-1542 IU/ml vs 1741IU/ml (p > 0.05); TP6-100% vs 100%, MAB-1961 IU/ml vs 2911 IU/ml (p > 0.05). At TP2, patients aged < 60 years (p < 0.001) were associated with maintaining seropositivity compared to patients > 60 years.

CONCLUSION

Two dose vaccination of haemodialysis patients provided poor nAB levels which improved markedly following 3rd dose vaccination, the effect of which was long- lasting with high nAB levels in both patients and controls detectable at 1 year follow-up.

Anti-SARS-CoV-2 spike antibody response to the third 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 the third dose 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 third dose of COVID-19 vaccine.

METHODS

Overall, 64 patients were enrolled in this single-center, prospective, longitudinal study. Anti-SARS-CoV-2 spike antibody titers were compared between hemodialysis patients and 18 healthcare workers. Multiple linear regression analysis was used to identify factors associated with the anti-SARS-CoV-2 spike antibody titer after the third vaccination.

RESULTS

There was no significant difference in anti-SARS-CoV-2 spike antibody titer 4 weeks after the third vaccination between hemodialysis patients and healthcare workers (18,500 [interquartile range, 11,000-34,500] vs. 11,500 [interquartile range, 7,918- 19,500], all values in AU/mL; p = 0.17). Uric acid (standard coefficient [β] = -0.203, p = 0.02), transferrin saturation (β = -0.269, p = 0.003), and log-anti-SARS-CoV-2 spike antibody titer 1 week before the third vaccination (β = 0.440, p < 0.001) correlated with the log-anti-SARS-CoV-2 spike antibody titer 4 weeks after the third vaccination. In contrast, only the log-anti-SARS-CoV-2 spike antibody titer 1 week before the third vaccination (β = 0.410, p < 0.001) correlated with the log- anti-SARS-CoV-2 spike antibody titer 12 weeks after the third vaccination.

CONCLUSION

The anti-SARS-CoV-2 spike antibody titer after the third dose of COVID-19 vaccine was comparable between hemodialysis patients and healthcare workers. Uric acid concentration, transferrin saturation, and anti-SARS-CoV-2 spike antibody titer before the third dose were associated with the anti-SARS-CoV-2 spike antibody titer after the third dose in Japanese hemodialysis patients.

Effectiveness and safety of immune response to SARS‑CoV‑2 vaccine in patients with chronic kidney disease and dialysis: A systematic review and meta‑analysis

The coronavirus disease 2019 (COVID-19) vaccination is the most effective way to prevent COVID-19. However, for chronic kidney disease patients on long-term dialysis, there is a lack of evidence regarding the efficacy and safety of the immune response to the vaccine. The present meta-analysis explores the efficacy and safety of COVID-19 vaccine in the immune response of patients with chronic kidney disease (CKD) undergoing dialysis. PubMed, Web of Science, Science Direct, and Cochrane Library databases were systematically searched from January 1, 2020, to December 31, 2022. Data analysis was performed using REVMAN 5.1s and Stata14 software. Baseline data and endpoint events were extracted, mainly including age, sex, dialysis vintage, body mass index (BMI), vaccine type and dose, history of COVID-19 infection, seropositivity rate, antibody titer, pain at injection site, headache and other safety events. The meta-analysis included 33 trials involving 81,348 patients. The immune efficacy of patients with CKD and dialysis was 80% (95 CI, 73-87%). The seropositivity rate of individuals without COVID-19 infection was 76.48% (3,824/5,000), while the seropositivity rate of individuals with COVID-19 infection was 80.82% (1,858/2,299). The standard mean difference of antibody titers in CKD and dialysis patients with or without COVID-19 infection was 27.73 (95% CI, -19.58-75.04). A total of nine studies reported the most common adverse events: Pain at the injection site, accounting for 18% (95 CI, 6-29%), followed by fatigue and headache, accounting for 8 (95 CI, 4-13%) and 6% (95 CI, 2-9%), respectively. COVID-19 vaccine benefitted patients with CKD undergoing dialysis with seropositivity rate ≥80%. Adverse events such as fatigue, headache, and pain at the injection site may occur after COVID-19 vaccination but the incidence is low.

Bidirectionality between Cardiometabolic Diseases and COVID-19: Role of Humoral Immunity

Cardiometabolic diseases and abnormalities have recently emerged as independent risk factors of coronavirus disease 2019 (COVID-19) severity, including hospitalizations, invasive mechanical ventilation, and mortality. Determining whether and how this observation translates to more effective long-term pandemic mitigation strategies remains a challenge due to key research gaps. Specific pathways by which cardiometabolic pathophysiology affects humoral immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and vice versa, remain unclear. This review summarizes current evidence of the bidirectional influences between cardiometabolic diseases (diabetes, adiposity, hypertension, CVDs) and SARS-CoV-2 antibodies induced from infection and vaccination based on human studies. Ninety-two studies among >408,000 participants in 37 countries on 5 continents (Europe, Asia, Africa, and North and South America) were included in this review. Obesity was associated with higher neutralizing antibody titers following SARS-CoV-2 infection. Most studies conducted prior to vaccinations found positive or null associations between binding antibodies (levels, seropositivity) and diabetes; after vaccinations, antibody responses did not differ by diabetes. Hypertension and CVDs were not associated with SARS-CoV-2 antibodies. Findings underscore the importance of elucidating the extent that tailored recommendations for COVID-19 prevention, vaccination effectiveness, screening, and diagnoses among people with obesity could reduce disease burden caused by SARS-CoV-2.

Booster effect of the third dose of SARS-CoV-2 mRNA vaccine in Japanese kidney transplant recipients

The humoral response of kidney transplant recipients (KTR) to the mRNA vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is generally poor. We evaluated the booster effect of the third dose (D3) of two SARS-CoV-2 mRNA vaccines 6 months after the second dose (D2) in Japanese KTR. The anti-spike (anti-S) antibody titer 1 and 3 months after the D3 was evaluated in 82 Japanese KTR. The primary endpoint was the seropositivity rate, and factors associated with the lack of a response were evaluated in a logistic regression model. Overall, the anti-S antibody seropositivity rate 1 and 3 months after the D3 was 74.7% and 76.0%. The anti-S antibody titers after the first and second doses were higher in patients vaccinated with the mRNA-1273 than with the BNT162b2 vaccine. Among the 38 KTR who were seronegative 5 months after the D2, 18 (47.4%) became seropositive following the D3. Factors associated with a non-response were mycophenolic acid dose, post-transplant duration, hemoglobin, and lymphocyte count. A humoral response 1 and 3 months after the D3 was obtained in ~ 75% of KTR, but 20% were non-responders. Additional studies are needed to clarify the factors hindering a vaccine response.

A Third Dose of SARS-CoV-2 mRNA Vaccine Improves Immune Response in Chronic Kidney Disease Patients

Chronic kidney disease (CKD) patients have an increased risk of morbidity and mortality following SARS-CoV-2 infection. Vaccination in these patients is prioritized, and monitoring of the immune response is paramount to define further vaccination strategies. This prospective study included a cohort of 100 adult CKD patients: 48 with kidney transplant (KT) and 52 on hemodialysis without prior COVID-19. The patients were assessed for humoral and cellular immune responses after four months of an anti-SARS-CoV-2 primary two-dose vaccination scheme (CoronaVac or BNT162b2) and one month after a booster third dose of BNT162b2 vaccine. We identified poor cellular and humoral immune responses in the CKD patients after a primary vaccination scheme, and these responses were improved by a booster. Robust polyfunctional CD4⁺ T cell responses were observed in the KT patients after a booster, and this could be attributed to a higher proportion of the patients having been vaccinated with homologous BNT162b2 schemes. However, even after the booster, the KT patients exhibited lower neutralizing antibodies, attributable to specific immunosuppressive treatments. Four patients suffered severe COVID-19 despite three-dose vaccination, and all had low polyfunctional T-cell responses, underscoring the importance of this functional subset in viral protection. In conclusion, a booster dose of SARS-CoV-2 mRNA vaccine in CKD patients improves the impaired humoral and cellular immune responses observed after a primary vaccination scheme.

Trajectory of Humoral Responses to Two Doses of ChAdOx1 nCoV-19 Vaccination in Patients Receiving Maintenance Hemodialysis

The ChAdOx1 nCoV-19 (AZD1222) vaccine is one of the most commonly delivered SARS-CoV-2 vaccines worldwide; however, few clinical studies have investigated its immunogenicity in dialysis patients. We prospectively enrolled 123 patients on maintenance hemodialysis at a medical center in Taiwan. All patients were infection-naive, had received two doses of the AZD1222 vaccine, and were monitored for 7 months. The primary outcomes were anti-SARS-CoV-2 receptor-binding domain (RBD) antibody concentrations before and after each dose and 5 months after the second dose and neutralization capacity against ancestral SARS-CoV-2, delta, and omicron variants. The anti-SARS-CoV-2 RBD antibody titers significantly increased with time following vaccination, with a peak at 1 month after the second dose (median titer, 498.8 U/mL; interquartile range, 162.5 to 1,050 U/mL), and a 4.7-fold decrease at 5 months. At 1 month after the second dose, 84.6, 83.7, and 1.6% of the participants had neutralizing antibodies against the ancestral virus, delta variant, and omicron variant, respectively, measured by a commercial surrogate neutralization assay. The geometric mean 50% pseudovirus neutralization titers for the ancestral virus, delta variant, and omicron variant were 639.1, 264.2, and 24.7, respectively. The anti-RBD antibody titers correlated well with neutralization capacity against the ancestral virus and delta variant. Transferrin saturation and C-reactive protein were associated with neutralization against the ancestral virus and delta variant. Although two doses of the AZD1222 vaccine initially elicited high anti-RBD antibody titers and neutralization against the ancestral virus and delta variant in hemodialysis patients, neutralizing antibodies against omicron variant were rarely detected, and the anti-RBD and neutralization antibodies waned over time. Additional/booster vaccinations are warranted in this population. IMPORTANCE Patients with kidney failure have worse immune response following vaccination compared to general population, but few clinical studies have investigated immunogenicity of ChAdOx1 nCoV-19 (AZD1222) vaccination in hemodialysis patients. Here, we showed two doses of AZD1222 vaccines lead to high seroconversion rate of anti-SARS-CoV-2 receptor-binding domain (RBD) antibodies, and more than 80% patients acquired neutralizing antibodies against ancestral virus and delta variant. However, seldom did they obtain neutralizing antibodies against the omicron variant. The geometric mean 50% pseudovirus neutralization titer against the ancestral virus was 25.9-fold higher than that against the omicron variant. Also, there was a substantial decay in anti-RBD titers with time. Our findings provided evidence supporting that more protective measures, including additional/booster vaccinations, is warranted in these patients during the current COVID-19 pandemic.

Seroconversion rates in kidney transplant recipients following SARS-CoV-2 vaccination and its association with immunosuppressive agents: a systematic review and meta-analysis

This systematic and meta-analysis aims to evaluate humoral and cellular responses to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine among kidney transplant recipients (KTRs). We conducted a systematic literature search across databases to evaluate seroconversion and cellular response rates in KTRs receiving SARS-CoV-2 vaccines. We extracted studies that assessed seroconversion rates described as the presence of antibody de novo positivity in KTRs following SARS-CoV-2 vaccination published up to January 23rd, 2022. We also performed meta-regression based on immunosuppression therapy used. A total of 44 studies involving 5,892 KTRs were included in this meta-analysis. The overall seroconversion rate following complete dose of vaccines was 39.2% (95% confidence interval [CI], 33.3%-45.3%) and cellular response rate was 41.6% (95% CI, 30.0%-53.6%). Meta-regression revealed that low antibody response rate was significantly associated with the high prevalence of mycophenolate mofetil/mycophenolic acid (p=0.04), belatacept (p=0.02), and anti-CD25 induction therapy uses (p=0.04). Conversely, tacrolimus use was associated with higher antibody response (p=0.01). This meta-analysis suggests that postvaccination seroconversion and cellular response rates in KTRs are still low. And seroconversion rate was correlated with the type of immunosuppressive agent and induction therapy used. Additional doses of the SARS-CoV-2 vaccine for this population using a different type of vaccine are considered.

Immunogenicity of COVID-19 vaccines in solid organ transplant recipients: a systematic review and meta-analysis

BACKGROUND

Solid organ transplant (SOT) recipients are at increased risks of morbidity and mortality associated with COVID-19.

OBJECTIVES

This study aimed to evaluate the immunogenicity of COVID-19 vaccines in SOT recipients.

DATA SOURCES

Electronic databases were searched for eligible reports published from 1 December 2019 to 31 May 2022.

STUDY ELIGIBILITY CRITERIA

We included reports evaluating the humoral immune response (HIR) or cellular immune response rate in SOT recipients after the administration of COVID-19 vaccines.

PARTICIPANTS

SOT recipients who received COVID-19 vaccines.

ASSESSMENT OF RISK OF BIAS

We used the Newcastle-Ottawa scale to assess bias in case-control and cohort studies. For randomised-controlled trials, the Jadad Scale was used.

METHODS

We used a random-effects model to calculate the pooled rates of immune response with 95% CI. We used a risk ratio (RR) with 95% CI for a comparison of immune responses between SOT and healthy controls.

RESULTS

A total of 91 reports involving 11 886 transplant recipients (lung: 655; heart: 539; liver: 1946; and kidney: 8746) and 2125 healthy controls revealed pooled HIR rates after the 1st, 2nd, and 3rd COVID-19 vaccine doses in SOT recipients were 9.5% (95% CI, 7-11.9%), 43.6% (95% CI, 39.3-47.8%) and 55.1% (95% CI, 44.7-65.6%), respectively. For specific organs, the HIR rates were still low after 1st vaccine dose (lung: 4.4%; kidney: 9.4%; heart: 13.2%; liver: 29.5%) and 2nd vaccine dose (lung: 28.4%; kidney: 37.6%; heart: 50.3%; liver: 64.5%).

CONCLUSIONS

A booster vaccination enhances the immunogenicity of COVID-19 vaccines in SOT; however, a significant share of the recipients still has not built a detectable HIR after receiving the 3rd dose. This finding calls for alternative approaches, including the use of monoclonal antibodies. In addition, lung transplant recipients need urgent booster vaccination to improve the immune response.

Humoral and cellular immune response and the safety of third SARS-CoV-2 mRNA vaccine with longer interval after the second vaccination in kidney transplant recipients

We evaluated the humoral and cellular immune responses and safety of the third severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine with a longer interval after the second vaccination in kidney transplant recipients (KTRs). We enrolled 54 kidney transplant recipients without a history of coronavirus disease 2019 (COVID-19), who received a third dose of the vaccine. We assessed anti-SARS-CoV-2 spike antibody and antigen-specific T cells using enzyme-linked immunospot (ELISpot) against the spike protein at baseline, after the second vaccination, and after the third vaccination. We also evaluated the adverse events related to each dose of the vaccine. The duration between the second and third vaccinations was 7 ± 1 month. All 17 (100%) KTRs with anti-SARS-CoV-2 antibody positivity after the second vaccination and 27 of 37 (73%) KTRs without anti-SARS-CoV-2 antibody positivity after the second vaccination were positive for anti-SARS-CoV-2 antibodies (p=0.022). Anti-SARS-CoV-2 antibody titers were significantly higher than those after the second vaccination (p<0.001). Age ≥ 60 years and lymphocyte count < 1150/mm³ were confirmed as risk factors for anti-SARS-CoV-2 antibody negativity after the third vaccination in multivariate regression analysis. ELISpot cytokine activities were positive after the third vaccination in 26 of 29 (90%) KTRs with ELISpot cytokine activity positivity after the second vaccination and 12 of 24 (50%) KTRs without ELISpot cytokine activity after the second vaccination. The rate of change in cytokine activity after the third vaccination was significantly higher than that after the second vaccination (p<0.001). Only lymphocyte counts less than 1150/mm³ were confirmed as risk factors for ELISpot cytokine activity negativity in the multivariate regression analysis. Systemic adverse events classified as greater than moderate did not differ for each vaccine dose. None of the patients showed clinical symptoms of acute rejection. The third SARS-CoV-2 mRNA vaccine administration, with a longer interval after the second vaccination, improved humoral and cellular immune responses to SARS-CoV-2 mRNA vaccines without severe adverse effects in the KTRs.

A systematic review assessing the effectiveness of COVID-19 mRNA vaccines in chronic kidney disease (CKD) individuals

Background: SARS-CoV-2 is a coronavirus that has rapidly spread across the world with a detrimental effect on the global population. Several reports have highlighted an increased mortality rate and a higher severity of COVID-19 infection in chronic kidney disease (CKD) individuals. Upon the development of various SARS-CoV-2 vaccines, mRNA vaccines including BNT162b2 and mRNA-1273 were deemed safe, with a high efficacy in preventing COVID-19 in the general population. This review investigates whether  SARS-CoV-2 mRNA vaccines are as effective in triggering an immune response in Dialysis Patients (DPs) and Kidney Transplant Recipients (KTRs) and if a third dose is required in this  population. Methods: A systematic search employing the PRISMA criteria was conducted in several major databases, with the data being extracted from publications for the period January 2021 to May 2022 (PROSPERO: CRD42022338514, June 15, 2022). Results: 80 studies were included in this analysis with a total cohort number of 15,059 participants. Overall, 85.29% (OR = 17.08, 95% CI = 15.84-18.42, I ² = 98%) and 41.06% (OR = 0.52, 95% CI = 0.48-0.5, I ² = 95%) of DPs and KTRs included in this review showed positive seroconversion after two doses of either mRNA vaccine, respectively. A total 76% (OR = 6.53, 95% CI = 5.63-7.5, I ² = 96%) of the cohort given a third dose of an mRNA vaccine demonstrated positive seroconversion, with 61.86% (OR = 2.31, 95% CI = 1.95-2.75 I ² = 95%) of the cohort that was assessed for a cellular response displaying a positive response. Conclusions: This data emphasises a reduced incidence of a positive immune response in DPs and KTRs compared to healthy controls, albeit a better response in DPs than when compared to KTRs alone was observed. A third dose  appears to increase the occurrence of an immune response in the overall DP/KTR cohort.

Long-term humoral immunity decline in hemodialysis patients following severe acute respiratory syndrome coronavirus 2 vaccination: A cohort study

BACKGROUND AND AIMS

Dialysis patients are extremely vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with high rates of hospitalization and mortality rates. In January 2021, the University of Virginia Dialysis Program initiated a program-wide vaccination campaign to administer the Pfizer BioNTech messenger RNA SARS-CoV-2 (BNT162b2) vaccine. The aim of this study was to characterize the long-term time-dependent decline in humoral immunity in hemodialysis patients.

METHODS

A prospective cohort study measuring serial monthly semiquantitative IgG antibody levels to the SARS-CoV-2 spike protein receptor binding domain in fully vaccinated in-center hemodialysis patients. Samples were collected monthly and tested for anti-SARS-CoV-2 antibodies against the anti-spike S1 domain for 2-6 months post full vaccination. Results were presented as internationally harmonized binding antibody units (BAU/ml). To analyze the change in antibody levels over time, a linear mixed model with random intercept and random slope was used for longitudinal antibody levels. A multivariable model was used to estimate the slope of antibody levels by adjusting for selected patient characteristics. Based on the estimated intercepts and slopes for each subject from the unadjusted model, 10-month antibody levels were projected.

RESULTS

The mean baseline antibody level was 647.59 BAU/ml and 87.88% (29/33) of patients were considered qualitatively positive. Two patients were negative at baseline and an additional two had borderline results. Patient antibody levels declined at an adjusted average rate of 31% per month. At 6 months postvaccination, 40% of patients remaining in the cohort possessed either negative or borderline IgG antibody levels. Projecting future antibody levels suggests that 65% of the cohort will progress to borderline or negative antibody levels at 10 months post full vaccination.

CONCLUSION

The long-term vaccine response following vaccination with the BNT162b2 in hemodialysis patients was characterized. Our data add to the limited pool of data in this patient population and emphasize the critical need for vaccine boosters.

Long-Term Humoral Response After a Second Dose of SARS-CoV-2 mRNA Vaccine in Japanese Kidney Transplant Recipients

Background

The mortality rate due to COVID-19 in kidney transplant recipients (KTRs) is 16.8 to 32%. Vaccination against COVID-19 is expected to contribute to the prevention of infection, severe disease, and mortality; however, it has been reported that the humoral response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine in KTRs is poor. Vaccination strategies against COVID-19 vary from country to country, and in Japan, the third dose is given 6 months after the second dose. Few studies have evaluated long-term humoral responses after the second dose of SARS-CoV-2 mRNA vaccine. In addition, the superiority of BNT162b2 vaccine and mRNA-1,273 vaccine in KTRs regarding humoral response is controversial.

Methods

Ninety-four KTRs were administered a second dose of the BNT162b2 or mRNA-1,273 vaccines, and anti-spike (anti-S) and anti-nucleocapsid (anti-N) SARS-CoV-2 antibody levels were measured 5 months (149.2 ± 45.5 days) later. The cutoff value of anti-S antibodies was defined ≥50 AU/ml and 1.4 Index for anti-N antibodies. The primary outcome was the rate of seropositivity, and factors associated with an appropriate humoral response were assessed by univariate and multivariate analysis.

Results

Of 94 KTRs, only 45 (47.9%) patients were positive for anti-S antibodies. The median anti-S SARS-CoV-2 IgG antibody titers was 35.3 (Interquartile range 3.8 to 159.7). Anti-N SARS-CoV-2 IgG antibodies in all patients were < 1.4 Index. Response to SARS-CoV-2 mRNA vaccines were 43.2 and 65% for BNT162b2 and mRNA-1,273, respectively (p = 0.152). In comparison with high-dose, low-dose of mycophenolic acid was a robust factor associated with an adequate humoral response.

Conclusion

The long-term humoral response after a second dose of SARS-CoV-2 mRNA vaccine in Japanese KTRs was poor. In comparison with high-dose, low-dose mycophenolic acid was related to an appropriate humoral response. Five months is too long to wait for a 3rd dose after 2nd dose of SARS-CoV-2 vaccine in KTRs. In this cohort, there was no statistical difference in humoral response to the BNT162b2 and mRNA-1,273 vaccines. Additional large observational studies and meta-analyses are needed to clarify the factors related to an appropriate humoral immune response to COVID-19 vaccination.

Evaluation of anti-severe acute respiratory syndrome coronavirus 2 antibody levels in coronavirus disease breakthrough infection during immunosuppressive therapy in a patient with connective tissue disease-related interstitial lung disease

Herein, we report the case of a 67-year-old man with severe coronavirus disease (COVID-19) pneumonia and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine breakthrough infection during immunosuppressive therapy for connective tissue disease-related interstitial lung disease (CTD-ILD). The patient received glucocorticoids combined with tacrolimus as maintenance therapy. His serum anti-SARS-CoV-2-immunoglobulin G (IgG) antibody levels were extremely low at the onset of COVID-19 pneumonia, even after the second dose of SARS-CoV-2 mRNA vaccine (BNT162b2). After treatment for COVID-19 pneumonia, the levels of anti-SARS-CoV-2-IgG antibodies increased. These results indicated a lack of the ability to produce neutralising antibodies from immune cells despite the booster vaccination. Therefore, we suggest that advanced-age patients with CTD-ILD receiving immunosuppressive therapy with polypharmacy require consistent personal protection, vaccination of close caregivers, increased awareness, and booster vaccination. Moreover, we recommend that tacrolimus should be withdrawn for a while after vaccination under controlled conditions.