Noncontrolled Trial of Monovalent AS03A-Adjuvanted Vaccine for 2009 Pandemic Influenza A(H1N1) in Long-term Dialysis Patients and Transplant Recipients

Long-Term Morbidity and Mortality of Coronavirus Disease 2019 in Patients Receiving Maintenance Dialysis: A Multicenter Population-Based Cohort Study

Key Points

The rates of long-term mortality, reinfection, cardiovascular outcomes, and hospitalization were high among coronavirus disease 2019 (COVID-19) survivors on maintenance dialysis. Several risk factors, including intensive care unit admission related to COVID-19 and reinfection, were found to have a prolonged effect on survival. This study shows that the burden of COVID-19 remains high after the period of acute infection in the population receiving maintenance dialysis.

Background

Many questions remain about the population receiving maintenance dialysis who survived coronavirus disease 2019 (COVID-19). Previous literature has focused on outcomes associated with the initial severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but it may underestimate the effect of disease. This study describes the long-term morbidity and mortality among patients receiving maintenance dialysis in Ontario, Canada, who survived SARS-CoV-2 infection and the risk factors associated with long-term mortality.

Methods

We conducted a population-based cohort study of patients receiving maintenance dialysis in Ontario, Canada, who tested positive for SARS-CoV-2 and survived 30 days between March 14, 2020, and December 1, 2021 (pre-Omicron), with follow-up until September 30, 2022. Our primary outcome was all-cause mortality while our secondary outcomes included reinfection, composite of cardiovascular (CV)–related death or hospitalization, all-cause hospitalization, and admission to long-term care or complex continuing care. We also examined risk factors associated with long-term mortality using multivariable Cox proportional hazards regression.

Results

We included 798 COVID-19 survivors receiving maintenance dialysis. After the first 30 days of infection, death occurred at a rate of 15.0 per 100 person-years (95% confidence interval [CI], 12.9 to 17.5) over a median follow-up of 1.4 years (interquartile range, 1.1–1.7) with a nadir of death at approximately 0.5 years. Reinfection, composite CV death or hospitalization, and all-cause hospitalization occurred at a rate (95% CI) of 15.9 (13.6 to 18.5), 17.4 (14.9 to 20.4), and 73.1 (66.6 to 80.2) per 100 person-years, respectively. In addition to traditional predictors of mortality, intensive care unit admission for COVID-19 had a prolonged effect on survival (adjusted hazard ratio, 2.6; 95% CI, 1.6 to 4.3). Reinfection with SARS-CoV-2 among 30-day survivors increased all-cause mortality (adjusted hazard ratio, 2.2; 95% CI, 1.4 to 3.3).

Conclusions

The burden of COVID-19 persists beyond the period of acute infection in the population receiving maintenance dialysis in Ontario with high rates of death, reinfection, all-cause hospitalization, and CV disease among COVID-19 survivors.

Impaired Immune Response to SARS-CoV-2 Vaccination in Dialysis Patients and in Kidney Transplant Recipients

Background

Patients with kidney failure on dialysis or after renal transplantation have a high risk for severe COVID-19 infection, and vaccination against SARS-CoV-2 is the only expedient prophylaxis. Generally, immune responses are attenuated in patients with kidney failure, however, systematic analyses of immune responses to SARS-CoV-2 vaccination in patients on dialysis and in kidney transplant recipients (KTRs) are still needed.

Methods

In this prospective, multicentric cohort study, antibody responses to COVID-19 mRNA vaccines (BNT162b2 [BioNTech/Pfizer] or mRNA-1273 [Moderna]) were measured in 32 patients on dialysis and in 28 KTRs. SARS-CoV-2-specific antibodies and neutralization capacity were evaluated and compared with controls (n=78) of a similar age range.

Results

After the first vaccination, SARS-CoV-2-specific antibodies were nearly undetectable in patients with kidney failure. After the second vaccination, 93% of the controls and 88% of patients on dialysis but only 37% of KTRs developed SARS-CoV-2-specific IgG above cutoff. Moreover, mean IgG levels were significantly lower in KTRs (54±93 BAU/ml) compared with patients on dialysis (503±481 BAU/ml; P<0.01). Both KTRs and patients on dialysis had significantly lower IgG levels compared with controls (1992±2485 BAU/ml; P<0.001 and P<0.01, respectively). Importantly, compared with controls, neutralizing antibody titers were significantly lower in KTRs and patients on dialysis. After the second vaccination, 76% of KTRs did not show any neutralization capacity against SARS-CoV-2, suggesting impaired seroprotection.

Conclusions

Patients with kidney failure show a significantly weaker antibody response compared with controls. Most strikingly, only one out of four KTRs developed neutralizing antibodies against SARS-CoV-2 after two doses of vaccine. These data suggest that vaccination strategies need modification in KTRs and patients on dialysis.Clinical Trial registry name and registration number: Vaccination Against COVID-19 in Chronic Kidney Disease, NCT04743947.

Comparison of Immunogenicity and Safety between a Single Dose and One Booster Trivalent Inactivated Influenza Vaccination in Patients with Chronic Kidney Disease: A 20-Week, Open-Label Trial

BACKGROUND

Non-dialysis-dependent chronic kidney disease (CKD-ND) patients are recommended to receive a one-dose influenza vaccination annually. However, studies investigating vaccine efficacy in the CKD-ND population are still lacking. In this study, we aimed to evaluate vaccine efficacy between the one-dose and two-dose regimen and among patients with different stages of CKD throughout a 20-week follow-up period.

METHODS

We conducted a single-center, non-randomized, open-label, controlled trial among patients with all stages of CKD-ND. Subjects were classified as unvaccinated, one-dose, and two-dose groups (4 weeks apart) after enrollment. Serial changes in immunological parameters (0, 4, 8, and 20 weeks after enrollment), including seroprotection, geometric mean titer (GMT), GMT fold-increase, seroconversion, and seroresponse, were applied to evaluate vaccine efficacy.

RESULTS

There were 43, 84, and 71 patients in the unvaccinated, one-dose, and two-dose vaccination groups, respectively. At 4-8 weeks after vaccination, seroprotection rates in the one- and two-dose group for H1N1, H3N2, and B ranged from 82.6-95.8%, 97.4-100%, and 73.9-100%, respectively. The concomitant seroconversion and GMT fold-increases nearly met the suggested criteria for vaccine efficacy for the elderly population. Although the seroprotection rates for all of the groups were adequate, the seroconversion and GMT fold-increase at 20 weeks after vaccination did not meet the criteria for vaccine efficacy. The two-dose regimen had a higher probability of achieving seroprotection for B strains (Odds ratio: 3.5, 95% confidence interval (1.30-9.40)). No significant differences in vaccine efficacy were found between early (stage 1-3) and late (stage 4-5) stage CKD.

CONCLUSIONS

The standard one-dose vaccination can elicit sufficient protective antibodies. The two-dose regimen induced a better immune response when the baseline serum antibody titer was low. Monitoring change in antibody titers for a longer duration is warranted to further determine the current vaccine strategy in CKD-ND population.

High-Dose Seasonal Influenza Vaccine in Patients Undergoing Dialysis

BACKGROUND AND OBJECTIVES

High-dose influenza vaccine, which contains fourfold more antigen than standard dose, is associated with fewer cases of influenza and less influenza-related morbidity in the elderly general population. Whether the high-dose influenza vaccine benefits patients on dialysis, whose immune response to vaccination is less robust than that of healthy patients, is uncertain.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared hospitalizations and deaths during the 2015-2016 and 2016-2017 influenza seasons by vaccine type (standard trivalent, standard quadrivalent, and high-dose trivalent influenza vaccine) administered within a national dialysis organization. The association of vaccine type with outcomes was estimated using Cox proportional hazards regression with adjustment for patient factors and "center effect." Analyses were stratified by age and dialysis modality.

RESULTS

Between September 1 and December 31, 2015, standard dose trivalent, standard dose quadrivalent, and high-dose trivalent influenza vaccines were administered to 3057 (31%), 5981 (61%), and 805 (8%) patients, respectively. The adjusted rates of first hospitalizations by vaccine type during the influenza season were 8.43, 7.88, and 7.99 per 100 patient-months, respectively, and the adjusted rates of death were 1.00, 0.97, and 1.04, respectively. These differences were not significant. In 2016, 3614 (39%) received quadrivalent vaccine, and 5700 (61%) received high-dose trivalent vaccine. The adjusted rates of first hospitalization by vaccine type were 8.71 and 8.04 per 100 patient-months, respectively, and the adjusted rates of death were 0.98 and 1.02, respectively. Receipt of high dose was associated with a significant reduction in hospitalization (hazard ratio, 0.93; 95% confidence interval, 0.86 to 1.00; P=0.04); there was no significant association with death. There was no significant heterogeneity of either association by age group or dialysis modality.

CONCLUSIONS

Receipt of high-dose compared with standard dose influenza vaccine in 2016-2017 was associated with lower rates of hospitalization in patients on dialysis, although that was not seen in 2015-2016.

Serum antibodies against native and denaturated hemagglutinin glycoproteins detected by ELISA as correlates of protection after influenza vaccination in healthy vaccinees and in kidney transplant recipients

The microneutralization assay is the standard method to investigate immune responses to influenza vaccination. However there remains some uncertainty as to whether ELISA results are a true measure of immunity in healthy or immuno-compromised vaccines. Furthermore it has been questioned if antibodies against native ("folded") and against denaturated ("unfolded") viral glycoproteins can equally be used as a marker of protection. In this study, two different quantitative IgG-ELISA assays detecting (i) antibodies against unfolded recombinant hemagglutinin (HA) (r-ELISA) and (ii) antibodies against the native HA on the influenza virus surface captured by fetuin-linkage (f-ELISA) were compared to microneutralization titers in sera from 29 healthy vaccinees (n=87 sera) and 39 kidney transplant recipients (n=117 sera) collected before, three weeks after and six months after vaccination against influenza A (H1N1) 2009. With both ELISAs a significant increase in antibody levels was detected after vaccination and linear regression analysis demonstrated that r-ELISA and f-ELISA correlated with microneutralization (R=0.622 for r-ELISA vs. R=0.56 for f-ELISA). For the healthy vaccinees both ELISAs were found to be adequate to distinguish protected from non-protected individuals (sensitivity and specificity: 87.5%/85.3% for r-ELISA and 87.5%/88.3% for f-ELISA). Results from the transplant recipients showed a slightly reduced sensitivity of 73.3% for r-ELISA while the f-ELISA demonstrated similar sensitivity and specificity as in the healthy vaccinees. However, in order to obtain these assay performances the cut-off-values for protection had to be adjusted for both assays and both investigation cohorts respectively limiting their application in routine laboratories.

[Concepts, effectiveness, and perspectives of pandemic and seasonal influenza vaccines]

For the first time in history, the conditions to influence the course of an influenza pandemic through vaccination were set during the influenza A H1N1 pandemic in 2009. The specific requirements for pandemic vaccines are to be highly immunogenic in immunologically naive individuals and to be producible quickly in large quantities. In contrast, seasonal influenza vaccines induce a booster response and a broadening of preexisting immunity. In this article the concepts of seasonal and pandemic influenza vaccines and data on their immunogenicity and clinical efficacy are reviewed and discussed. In the upcoming years, seasonal influenza vaccination will continue to be based on inactivated split-virion and subunit vaccines or the live attenuated cold-adapted vaccine. The pandemic vaccines used in 2009 proved to be more immunogenic than expected from prepandemic vaccine trials, while the adverse events observed with AS03-adjuvanted vaccines call their future use into question. However, neither seasonal nor pandemic influenza vaccines can be regarded to be an ideal solution, because they have to be frequently adapted to new virus strains and they lack effectiveness in particular risk groups. They can be regarded as interim approaches to highly immunogenic vaccines that hopefully become available in the future. The underlying principles of future vaccines are also presented in this article.

Poor seroprotection but allosensitization after adjuvanted pandemic influenza H1N1 vaccine in kidney transplant recipients

BACKGROUND

Seasonal and pandemic influenza virus infections in renal transplant patients are associated with poor outcomes. During the pandemic of 2009-2010, the AS03-adjuvanted monovalent H1N1 influenza vaccine was recommended for transplant recipients, although its immunogenicity in this population was unknown. We sought to determine the safety and immunogenicity of an adjuvant-containing vaccine against pandemic influenza A H1N1 2009 (pH1N1) administered to kidney transplant recipients.

METHODS

We prospectively enrolled 124 adult kidney transplant recipients in the fall of 2009 at two transplant centers. Cohort 1 (n = 42) was assessed before and after pH1N1 immunization, while Cohort 2 (n = 82) was only assessed post immunization. Humoral response was measured by the hemagglutination inhibition assay. Vaccine safety was assessed by adverse event reporting, graft function, and human leukocyte antigen (HLA) alloantibody measurements.

RESULTS

Cohort 1 had a low rate of baseline seroprotection to pH1N1 (7%) and a low rate of seroprotection after immunization (31%). No patient <6 months post transplant (n = 5) achieved seroprotection. Seroprotection rate was greater in patients receiving double as compared with triple immunosuppression (80% vs. 24%, P = 0.01). In Cohort 2, post-immunization seroprotection was 35%. In both cohorts, no confirmed cases of pH1N1 infection occurred. No difference was seen in estimated glomerular filtration rate before (54.3 mL/min/1.73 m(2) ) and after (53.8 mL/min/1.73 m(2) ) immunization, and no acute rejections had occurred after immunization at last follow-up. In Cohort 1, 11.9% of patients developed new anti-HLA antibodies.

CONCLUSION

An adjuvant-containing vaccine to pH1N1 provided poor seroprotection in renal transplant recipients. Receiving triple immunosuppression was associated with a poor seroresponse. Vaccination appeared safe, but some patients developed new anti-HLA antibodies post vaccination. Alternative strategies to improve vaccine responses are necessary.