Adequate seroresponse to influenza vaccination in dialysis patients

BACKGROUND: Hemodialysis (HD) patients are immunocompromised, and they have been shown to react suboptimally to recommended vaccinations. Advances in dialysis therapy and other supportive measures may theoretically result in better immune system functions. Clinical evidence supporting this theory has, however, not been presented. With influenza vaccination response, we tried to address this question. METHODS: 42 HD and 15 continuous ambulatory peritoneal dialysis (CAPD) patients were vaccinated with a trivalent influenza vaccine, and the seroresponses at 5 weeks were measured. The results were compared with those of similarly vaccinated 20 nephrology outpatient clinic patients with varying degrees of renal insufficiency and those of 31 cardiac patients with normal renal function. RESULTS: The dialysis patients had higher prevaccination titers of hemagglutination-inhibiting (HI) antibodies to all three vaccine virus antigens than the other groups due to more frequent previous vaccinations. The dialysis patients exhibited lower antibody increases, but an almost comparable proportion of them reached a protective antibody level (HI titers > or =40) 5 weeks after vaccination [A/H3N2: 61% (cardiac patients), 35% (nephrology outpatient clinic patients), 67% (CAPD), and 36% (HD); A/H1N1: 71, 70, 80 and 60; B: 97, 90, 80, and 76%, respectively]. Among the HD group, all patients receiving parenteral calcitriol except 1 (83%), but only 50% of the other HD patients produced protective antibody titers at least to two out of three vaccine virus antigens. No other patient- or HD treatment-associated parameter was significantly related to the vaccination-induced antibody response. CONCLUSIONS: We conclude that influenza vaccination of dialysis patients according to current recommendations may be effective. Additionally, our results suggest that parenteral calcitriol treatment may augment the immune response of HD patients even in a clinically relevant way, an effect so far shown only in in vitro studies.     

Intact humoral immune response in patients on continuous ambulatory peritoneal dialysis

After influenza vaccination no statistically significant difference in antibody response was observed between patients on continuous ambulatory peritoneal dialysis (CAPD) and healthy volunteers while a large group of hemodialysis (HD) patients was found to have a significantly lower response rate. This difference remained statistically significant when CAPD patients were compared to a matched HD group. As the antibody formation after influenza vaccination is a T cell-dependent phenomenon, the normal immune response to vaccination suggests an intact humoral and cellular immunity in CAPD patients.     

Active influenza immunization in hemodialysis patients: comparison between single-dose and booster vaccination

BACKGROUND/AIMS: Hemodialysis (HD) patients are recommended to be immunized against influenza annually, but the immune response after vaccination is known to be weakened in these patients. We intended to compare the efficacy of influenza vaccines in HD patients with that in healthy people, and we also evaluated the additive effect of a booster vaccination in HD patients. METHODS: During the 2003-2004 influenza season, 100 patients on HD and 50 age-matched healthy controls were recruited from the Korea University Guro Hospital. The HD patients were divided into two groups: single-dose group (50 patients) and booster group (50 patients). Eight weeks following the influenza vaccination, the serum antibody responses were compared. RESULTS: Although the antibody response of the HD patients was impaired in comparison with that of healthy controls, more than 90% of the HD patients showed protective antibody levels. Booster vaccination did not significantly increase the immune response in HD patients. CONCLUSIONS: Influenza vaccination in HD patients should be encouraged, but the immune response was comparatively impaired in subpopulations, including patients with a long-term HD history (>2.5 years), with a higher urea reduction rate, or with underlying diabetes. There was no effect of a booster vaccine dose on the antibody titers.     

Seasonal Maintenance of Influenza Vaccine-Induced Antibody Response in Kidney Transplant Recipients

Background/Aims: Although annual influenza vaccination is recommended for kidney transplant recipients, efficacy as reflected by serum antibody titers has not been well studied beyond 1 month in kidney transplant recipients. Methods: We performed a single-center prospective cohort study of 51 kidney transplant recipients and 102 healthy controls receiving the 2006-2007 influenza vaccine. Anti-hemagglutinin antibody titers to A/H1N1, A/H3N2, and B were measured before and 1 month after vaccination, and again at the end of influenza season. The primary outcome was the proportion of participants maintaining seroprotection (antibody titer ≥1:32) for the duration of the influenza season after influenza vaccination. Results: Median follow-up time was 175 and 155 days in the transplant and control groups, respectively. For types A/H1N1 and B, a similar high proportion of the transplant and control groups (88.5 and 81.6% vs. 83.7 and 74.2% for A/H1N1 and B, respectively) maintained seroprotection. For type A/H3N2, significantly less of the transplant group (66.7%) versus the control group (90%) maintained a protective influenza vaccine response (odds ratio 0.21, 95% confidence interval 0.07-0.64). This difference disappeared in adjusted analyses. Actual geometric mean titers decreased significantly within both groups (p < 0.001) but this did not differ between groups. Conclusions: Once they have developed protective vaccine-induced antibody responses to influenza vaccine, kidney transplant recipients are able to maintain adequate protective levels of antibody compared with healthy controls.     

Antibody response to influenza A vaccination in children with nephrotic syndrome

The aim of this study was to determine the antibody response to influenza vaccination in children with nephrotic syndrome (NS). Nineteen children with NS and 10 healthy controls were vaccinated with a 1999–2000 influenza vaccine. A dose of 0.25 ml was used for those under 6 years and 0.5 ml for those over 6 years. All children were given two doses with a month between each dose. Antibody titers were measured before vaccination and 1 month after vaccination in both groups and 6 months after vaccination in 8 patients with NS. The proportion of subjects in the nephrotic group with protective antibody titers before immunization (10.5%) was significantly lower than the proportion at 1 (78.9%) and 6 months (87.5%) post vaccination. The mean concentration of specific IgG antibodies to influenza A in the NS group increased 6-fold at 1 month and approximately 14-fold at 6 months. These results suggest that pediatric patients with NS have an adequate antibody response to influenza A vaccine. Protective antibody titers to influenza A were maintained at 6 months after immunization in 8 patients with NS.     

Hepatitis B vaccination in human immunodeficiency virus-infected adults receiving hemodialysis

BACKGROUND: The Centers for Disease Control and Prevention (CDC) recommends hepatitis B virus (HBV) immunization for all hemodialysis (HD) patients because they are at high risk of infection. Several studies have shown that the development of protective antibody titers after HBV vaccination is much lower in HD patients. We hypothesized that human immunodeficiency virus (HIV) infection in patients with end-stage renal disease (ESRD) would further impair the immune response to hepatitis B vaccination. METHODS: We performed a retrospective cohort study of patients undergoing long-term hemodialysis from 1990 to 2002 at the United States-based dialysis facilities of Gambro Corporation, North America. The response rate defined as an increase in anti-HBs levels >/=10 mIU/L after a month of the third dose of HBV vaccination was determined in HIV-infected and a randomly selected group of ESRD patients. The demographic information, laboratory data, and hepatitis B surface antibody (anti-HBs) titers were recorded from the Gambro Corporation database on these patients. RESULTS: Of the 347 adult HIV ESRD patients, 116 received three doses of recombinant hepatitis B vaccination. Seventy percent were male, and the majority (86%) were black. Of the 116 patients who received three doses of HBV vaccination, 62 (53.4%) developed protective antibody titers. This was comparable to the response rate of 50.4% in the randomly selected 220 non-HIV hemodialysis patients. Among HIV ESRD patients, the mean hemoglobin (Hgb) was higher in patients who developed protective antibody titers (Hgb 11.61 +/- 2 vs. 10.55 +/- 1.86, P value <0.01). On multivariate logistic regression analysis, higher Hgb was associated with protective antibody titers (odds ratio: 1.34, 95% CI 0.99-1.72). Seventy percent of the HIV-infected responders maintained protective antibody titers 6 months after vaccination. CONCLUSION: Hepatitis B vaccination should be offered to all HIV-infected ESRD patients because over half of the patients with HIV and ESRD can develop protective antibodies.     

Impairment of the immune response to influenza vaccination in renal transplant recipients by cyclosporine, but not azathioprine

Influenza vaccination has been strongly recommended for immunosuppressed renal transplant recipients. However, immunosuppression may lead to impaired antibody responses. We studied the antibody response to an inactivated trivalent influenza vaccine in 59 renal transplant recipients with life-sustaining kidney function: 21 were on cyclosporine and prednisone, 38 on azathioprine and prednisone. Healthy volunteers (n = 29) and patients on hemodialysis (n = 28) served as controls. Despite comparable renal allograft function, cyclosporine-treated patients had a significantly lower immune response against influenza A viruses than azathioprine-treated patients, whether mean antibody levels, fourfold titer rise, or seroconversion to protective titers was analyzed. No significant differences in antibody responses were found between healthy controls and patients on azathioprine. The patients on hemodialysis showed an impaired response to vaccination. However, in contrast to the cyclosporine-treated patients, booster immunization proved valuable in this group.     

Influenza vaccination in heart transplant recipients.

Seventy-nine heart transplant recipients were vaccinated with a trivalent influenza virus vaccine 1996/97 containing the strains A/Singapore/6/86 (H1N1), A/Wuhan/395/95 (H3N2), and B/Beijing/184/93. The proportions of patients with protective levels of antibody (HI > or = 40) after vaccination ranged from 100% (A/Singapore [H1N1]) to 31.6% (B/Beijing) and their mean fold titer increases were lower than those recorded for vaccination of 109 healthy subjects with the same batch of vaccine. The vaccinations were tolerated well and did not result in serious side effects, such as graft rejections. Our findings indicate that influenza vaccination can induce protective antibody levels in a substantial proportion of heart transplant recipients and lend support to the recommendation to vaccinate such patients annually against influenza.     

Influenza vaccination in chronic hemodialysis patients. The effect of zinc supplementation.

Since influenza increases the mortality of chronically ill patients we decided to study the effectiveness of influenza vaccination in hemodialysis (HD) patients. Nineteen HD patients aged from 20 to 60 years, on unrestricted diet and with no febrile episode, were studied. Blood samples were collected before the intramuscular injection of 0.5 mL multivalent influenza vaccine (Inflexal Berna) and every 2 weeks thereafter. At the end of 4th week a second vaccination was done and a dosage of 200 mg of zinc acetate (60 mg elemental zinc) was given daily to each patient for at least 4 weeks. Before vaccination the antibody titers to influenza virus ranged from 1:10 to 1:80 and after vaccination from 1:20 to 1:640. Four weeks after vaccination 6/19 (31.5%), 8/19 (42%), and 10/19 (52.5%) patients showed a fourfold or greater increase at serum antibody titers to antigens A/Singapore, A/Sichuan, and B/Beijing, respectively. The zinc supplementation after the second vaccination induced a similar increase of serum antibody titers to the A/Singapore but some even greater increase of the antibody titers to the A/Sichuan and B/Beijing. Serum immunoglobulins and complement components C3/C4 were not changed during this study. It is suggested that about 50% of uremic patients respond to the influenza vaccination and that zinc treatment does not increase this responsiveness.     

Influenza Vaccination in Chronic Hemodialysis Patients. The Effect of Zinc Supplementation

Since influenza increases the mortality of chronically ill patients we decided to study the effectiveness of influenza vaccination in hemodialysis (HD) patients. Nineteen HD patients aged from 20 to 60 years, on unrestricted diet and with no febrile episode, were studied. Blood samples were collected before the intramuscular injection of 0.5 mL multivalent influenza vaccine (Inflexal Berna) and every 2 weeks thereafter. At the end of 4th week a second vaccination was done and a dosage of 200 mg of zinc acetate (60 mg elemental zinc) was given daily to each patient for at least 4 weeks. Before vaccination the antibody titers to influenza virus ranged from 1:10 to 1:80 and after vaccination from 1:20 to 1:640. Four weeks after vaccination 6/19 (31.5%), 8/19 (42%), and 10/19 (52.5%) patients showed a fourfold or greater increase at serum antibody titers to antigens A/Singapore, A/Sichuan, and B/Beijing, respectively. The zinc supplementation after the second vaccination induced a similar increase of serum antibody titers to the A/Singapore but some even greater increase of the antibody titers to the A/Sichuan and B/Beijing. Serum immunoglobulins and complement components C₃/C₄ were not changed during this study. It is suggested that about 50% of uremic patients respond to the influenza vaccination and that zinc treatment does not increase this responsiveness.     

Evaluation of immune responses to seasonal influenza vaccination in healthy volunteers and in patients after stem cell transplantation

BACKGROUND: Influenza causes significant morbidity and mortality in immunocompromised stem cell transplantation (SCT) recipients. Measurement of cellular and humoral immunological responses might increase our understanding of how to estimate a protective response to influenza vaccination. METHODS: Eighteen healthy subjects and 14 SCT patients tested before and 4 weeks after influenza vaccination were included in the study. Peripheral blood lymphocytes were stimulated with influenza peptides and Enzyme-Linked ImmunoSpot assays to measure the production of intracellular interferon-gamma, interleukin-4 and interleukin-13. Prelabeled major histocompatibility complex class I pentamers were used for the detection of influenza-specific CD8+ T-cells. B-cell Enzyme-Linked ImmunoSpot and hemagglutination inhibition assays were performed to enumerate influenza-specific antibody-secreting cells and titer of neutralizing antibodies. RESULTS: Influenza vaccination elicited strong cell-mediated immune responses in the healthy controls (P< or =0.003 for all four peptides) and SCT patients (P< or =0.008). The percentage of CD8+ specific cells increased significantly after vaccination both in volunteers (P=0.005) and in patients (P< or =0.003). The number of influenza-specific antibody-secreting cells increased after vaccination both in volunteers (P=0.009) and in patients (P=0.01). Twenty-nine percent of SCT patients demonstrated protective antibody levels to influenza A H1/N1 serotype. CONCLUSIONS: Seasonal vaccination against influenza boosts the cellular immune response both in SCT patients and healthy controls. The protective effect is lower in the patients in general and especially on those, vaccinated early after SCT.     

Thyroid function and morphology in kidney transplant recipients, hemodialyzed, and peritoneally dialyzed patients

Disturbances in thyroid function are common among patients on renal replacement therapy. The aim of the present study was to compare thyroid stimulating hormone (TSH) and thyroid morphology among patients on hemodialysis (HD), peritoneal dialysis (CAPD), and after kidney transplantation. The study was performed on three groups of patients: 48 transplant recipients (Tx) (receiving cyclosporine, azathioprine, and prednisone); 32 HD, and 26 CAPD patients. The control group included 40 healthy volunteers. Thyroid examinations were performed with a 7.5-MHz probe and the thyroid volume was calculated. Among Tx patients the thyroid volume was 25.16 +/- 12.27mL; 21.60 +/- 10.33mL in HD; 19.70 +/- 8.46 mL in CAPD; and 16.34 +/- 5.46mL in the healthy volunteers. Serum TSH was within the normal range in each group. Goiter was diagnosed in the majority of Tx, most HD patients, and some CAPD patients. Single and multiple nodules were found in 21 Tx, 12 HD, and 2 CAPD patients. Moreover, parathyroid glands were visualized on sonography in 10 Tx, 12 HD, and 8 CAPD subjects. In Tx observed correlations were positive between thyroid volume and creatinine, negative between thyroid volume and TSH. The time after transplantation correlated negatively with TSH. No correlation between TSH, thyroid volume, and time on dialysis was observed. The prevalence in patients on renal replacement therapy was higher than that in the general population. These findings suggest that screening for abnormal thyroid morphology should be performed in kidney patients and that iodide supplementation should be considered in Tx patients.     

Lack of serologic immunity against vaccine‐preventable diseases in children after thoracic transplantation

We investigated whether children after heart‐ (HTx) or heart–lung transplantation (HLTx) show protective antibody levels against recommended vaccinations, whether vaccination schedules are completed and which factors influence serologic immunity. We performed a cross sectional ELISA – quantification of specific antibodies in 46 patients after pediatric thoracic Tx. Findings were correlated to vaccination history, age at Tx, clinical course and immunosuppressive regimen. We found protective antibody levels against diphtheria in 74% of patients, against tetanus in 22%, against Haemophilus influenzae type b in 30% and against Streptococcus pneumoniae in 59%. Antibody concentrations against live attenuated vaccines were significantly lower in children transplanted in the first 2 years of life. Antibodies were absent for measles in 55% of late – and 81% of early transplanted children, for mumps in 66%/94%, for rubella in 30%/56% and for Varicella in 34%/63%. We found significant correlation of low antibody concentrations and age at Tx. Patients without protective antibody concentrations had significantly longer use of steroids. Vaccination schedules were incomplete or delayed in the majority of patients associated with more days in hospital pre‐Tx. Our study shows that closer adherence to pretransplantation vaccination schedules and also post‐transplantation monitoring of antibody levels are required in transplant patients.     

Immunogenicity and Safety of an Intradermal Boosting Strategy for Vaccination Against Influenza in Lung Transplant Recipients

The immunogenicity of influenza vaccine is suboptimal in lung transplant recipients. Use of a booster dose and vaccine delivery by the intradermal rather than intramuscular route may improve response. We prospectively evaluated the immunogenicity and safety of a 2-dose boosting strategy of influenza vaccine. Sixty lung transplant recipients received a standard intramuscular injection of the 2006-2007 inactivated influenza vaccine, followed 4 weeks later by an intradermal booster of the same vaccine. Immunogenicity was assessed by measurement of geometric mean titer of antibodies after both the intramuscular injection and the intradermal booster. Vaccine response was defined as 4-fold or higher increase of antibody titers to at least one vaccine antigen. Thirty-eight out of 60 patients (63%) had a response after intramuscular vaccination. Geometric mean titers increased for all three vaccine antigens following the first dose (p < 0.001). However, no significant increases in titer were observed after the booster dose for all three antigens. Among nonresponders, 3/22 (13.6%) additional patients responded after the intradermal booster (p = 0.14). The use of basiliximab was associated with a positive response (p = 0.024). After a single standard dose of influenza vaccine, a booster dose given by intradermal injection did not significantly improve vaccine immunogenicity in lung transplant recipients.     

Granulocyte-macrophage colony-stimulating factor as an adjuvant to hepatitis B vaccination in maintenance hemodialysis patients

Patients on maintenance hemodialysis (HD) have poor seroconversion rate after hepatitis B vaccination. The present study was designed to test the efficacy of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant to hepatitis B vaccination for improving seroconversion rate in maintenance HD patients. Twelve chronic HD patients were randomly assigned to receive either hepatitis B vaccination alone or hepatitis B vaccination 24 h after 1 dose of GM-CSF for primary immunization. A group of 16 chronic HD patients who had not seroconverted after a standard two-dose hepatitis B vaccination were randomly assigned either to a booster dose of hepatitis B vaccine alone or a booster dose given 24 h after one dose of GM-CSF. In the primary immunization group only 2 of 6 patients (33%) who had received vaccination alone, versus 5 of 6 patients (83%) who had received hepatitis B vaccine after one dose of GM-CSF, developed seroprotective antibody titers. Moreover, seroprotective antibody titers (IU/ml) were significantly higher in the latter group (275 +/- 286.5 vs. 14 +/- 22, p < 0.05). In patients who had not seroconverted with prior hepatitis B vaccination, GM-CSF adjuvant therapy significantly increased the seroconversion rate versus booster dose alone (87.5 vs. 25%, respectively, p < 0.02), with significantly higher seroprotective antibody titers (84 +/- 80 vs. 19 +/- 33 IU/ml, respectively, p < 0. 05). These findings suggest that administration of one dose of GM-CSF, as adjuvant therapy, prior to primary or booster dose hepatitis B vaccination may significantly increase seroconversion rate and seroprotective antibody titers in chronic HD patients.     

Influenza virus immunization effectivity in kidney transplant patients subjected to two different triple-drug therapy immunosuppression protocols: mycophenolate versus azathioprine

BACKGROUND: Due to possible complications and treatment limitations, the prevention of influenza in renal transplant (RT) patients is highly indicated. METHODS: Forty-nine patients with a 1-year functioning RT subjected to two different immunosuppressive regimens and 37 healthy relatives (HR) were administered the anti-influenza vaccine as recommended for 1996 to 1997. Anti-influenza antibody, creatinine, and immunological markers were estimated at 1 and 3 months after vaccination. RESULTS: Three months after vaccination, 46.2% of the RT patients and 69% of the HR (P=0.06) showed protective antibody titers to influenza A (relative risk [RR]; 0.67; 95% confidence interval: 0.44-1.02). A total of 20.5% of the RT patients and 44.8% of the HR showed antibodies to influenza B (P=0.03). Despite these differences, the incidence of illness was similar. The immunosuppressive regimen had no effect on the antibody response. CONCLUSIONS: Although the RT patients showed a reduced antibody response, no negative effects on graft outcome were observed.     

Influenza Vaccination in Orthotopic Liver Transplant Recipients: Absence of Post Administration ALT Elevation

Influenza vaccination has reduced life-threatening complications from influenza virus infection in adult liver transplant recipients. We evaluated changes in aminotransferase level and immunogenicity of influenza vaccination in liver transplant recipients. Fifty-one liver transplant recipients were administered a standard dose of the 2002-2003 inactivated trivalent influenza vaccine. ALT values were measured at baseline, 1 week and 4-6 weeks postvaccination. Antibody responses to each component of the vaccine were measured at baseline and after 4-6 weeks by a hemagglutination inhibition (HAI) assay. Response was defined as an HAI titer > or = 1: 40 and/or a 4-fold increase in antibody titers from baseline. An ALT elevation was defined as a rise of > or = 50% from baseline. There was no difference in the median rise in ALT value between seroconverters and nonseroconverters. A significant number of recipients developed potentially protective antibody titers (p-value < 0.0001). At less than 4 months post transplantation, 1/7 (14%), at 4-12 months, 6/9 (67%), and after 12 months, 30/35 (86%) subjects responded to the H1 strain. Of 51 recipients, one HCV (-) recipients vaccinated within 3 months of transplantation developed acute cellular rejection. Influenza virus vaccination is not associated with allograft rejection or ALT flares in liver transplant recipients.     

The evaluation of immune responses to hepatitis B vaccination in diabetic and non-diabetic haemodialysis patients and the use of tetanus toxoid

Aim: The aim of this study was to investigate whether haemodialysis (HD) patients suffering from diabetes mellitus could be considered at risk for the development of the protective antibodies to hepatitis B (HB) vaccination and, to evaluate the effectiveness of tetanus toxoid (TT) administrated 2 days before HB vaccination. Methods: Forty-nine HD patients were divided into two groups: group A (19 diabetic patients) and group B (30 non-diabetic patients). A dose of 40 μg recombinant HB vaccine was injected intramuscularly to the patients at 0, 1, 2 and 6 months. Results: After the completion of the course, the patients in group A were found to have a lower protective antibody rates than the patients in group B (57.8% vs 70%) (P > 0.05). After the administration of additional booster doses during 12 months, the protective antibody to hepatitis B surface antigen (HBsAb) levels were detected in 78.9% and 96.6% of the patients in group A and group B, respectively (P > 0.05). The patients not having protective HBsAb levels were administered TT and HB vaccines, and after course, all of them have produced protective HBsAb levels. Conclusion: The present study showed that diabetic patients on HD may carry a greater risk of not seroconverting than non-diabetic ones for antibody response to HB vaccination. The use of TT 2 days before HB vaccination may be a useful and effective method of enhancing the immune response to HB vaccination, especially in the patients with diabetes mellitus on HD.     

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

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is shown to prevent severe illness and death in hemodialysis (HD) patients, but the immune response to vaccines is reduced in this population. This study compared SARS-CoV-2 spike protein antibody titers between HD patients and healthy controls in Japan for up to 6 months following vaccination.

Methods

A multi-institutional retrospective study at five clinics in Japan was conducted using 412 HD patients and 156 healthy controls who received two doses of the BNT162b2 (Pfizer-BioNTech) mRNA vaccine. Anti-SARS-CoV-2 spike protein S1 IgG antibody titers were measured at 1, 3, and 6 months after the second dose. The attenuation speed was calculated as slope (i.e., –β) using a linear mixed-effects model toward the log-transformed antibody titers.

Results

The HD group had significantly lower month 1 antibody titers (Ab-titer-1) than the controls, and these remained lower through month 6 (95% CI: 2617.1 (1296.7, 5240.8) vs. 7285.4 (4403.9, 11,000.0) AU/mL at Ab-titer-1, and 353.4 (178.4, 656.3) vs. 812.0 (498.3, 1342.7) AU/mL at Ab-titer-6 (p?<?0.001, respectively)). Lower log Ab-titer-1 levels in the HD group were significantly associated with a lower log Ab-titer–6 (0.90 [0.83, 0.97], p?<?0.001). The –β values in the HD patients and healthy controls were –4.7?±?1.1 and –4.7?±?1.4 (year^?1), respectively.

Conclusion

SARS-CoV-2 spike protein antibody titers were significantly lower in HD patients than in healthy controls at 1 (peak) and 6 months after the second vaccination. Low peak antibody titers contributed to low 6-month antibody titers.

     

The Effect of Sirolimus Therapy on Vaccine Responses in Transplant Recipients

Different immunosuppressant regimens vary in their effects on antibody responses to vaccination. The combination of prednisolone and azathioprine has only a minor effect, whereas the addition of ciclosporin attenuates protective antibody responses to influenza vaccination. The effect of sirolimus, a new immunosuppressant, on vaccine responses has been little studied. Thirty-two hepatic or renal transplant patients randomized to calcineurin inhibitor-based or sirolimus-based immunosuppression were vaccinated against influenza and pneumococcus. Following tri-valent influenza vaccination, a similar rise in antibody titer occurred in sirolimus and calcineurin inhibitor (CNI) treated patients, though sirolimus treated patients developed a 'protective' titer to more influenza antigens. The pneumococcal polysaccharide vaccine was equally effective in both groups. Hence, vaccination guidelines in place for CNI treated patients are likely to be appropriate for transplant recipients maintained on sirolimus.