Effectiveness of Three Doses of mRNA COVID-19 Vaccines in the Hemodialysis Population during the Omicron Period

Omicron variant infection worsen the prognosis of haemodialysis (HD) patients

BACKGROUND

Haemodialysis (HD) patients are predisposed to physical ailments, and their occurrence of coronavirus disease 2019 (COVID-19) could potentially lead to a more unfavourable prognosis. However, the impact of SARS-CoV-2 (Omicron variant) infection on the prognosis of HD patients remains unclear. This study aimed to explore the impact of Omicron variant infection on the prognosis of HD patients.

METHODS

Eligible participants were patients undergoing maintenance HD treatment during a large-scale outbreak of COVID-19 (Omicron variant) in Shanghai, China, from April 7 to May 30, 2022. According to SARS-CoV-2 infection status of participants, the HD patients were divided into two groups: a COVID-19 group and a non-COVID-19 group. The primary outcome assessed was in-hospital mortality, and secondary outcomes encompassed the incidence of severe cases, admission to intensive care, length of hospital stay, and blood indices. Statistical analysis was conducted by comparative analysis and multiple logistic regression.

RESULTS

This study recruited 588 HD patients, including 199 cases in the COVID-19 group and 389 in the non-COVID-19 group. In the COVID-19 group, the mortality rate was 8.45% (17/199), whereas in the non-COVID-19 group, the rate was 3.34% (13/389) (p < 0.05). Compared with the non-COVID-19 group, the COVID-19 group had a risk ratio (RR) with 95% confidence interval (CI) of 2.56 (1.27-5.15) for mortality, and the absolute risk difference (ARD) with 95% CI of 5.20% (1.34%-9.06%). Multiple logistic regression confirmed Omicron variant as a risk factor for mortality among HD patients. Additionally, the COVID-19 group had a higher proportion of severe cases, intensive care admission, hypocalcaemia and hyperphosphatemia and longer hospitalization duration, compared to the non-COVID-19 group (p < 0.05).

CONCLUSIONS

Omicron variant infection was associated with increased mortality risk in HD patients, and Omicron infection worsen the prognosis of HD patients. Enhancing immune protection against SARS-CoV-2 is crucial for HD patients during the ongoing COVID-19 pandemic.

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.

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.

Clinical characteristics and outcomes of maintenance hemodialysis patients with COVID-19 during the Omicron wave of the pandemic in Beijing: a single center retrospective study

BACKGROUND

The clinical manifestations and prognosis of hemodialysis patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) during the Omicron wave of the pandemic infection were still unclear. This study investigated the clinical characteristics of patients undergoing maintenance hemodialysis (MHD) infected with it.

METHODS

This retrospective single-center study included 151 patients undergoing MHD. Healthcare workers were selected as control group were assessed from December 1, 2022 to March 31, 2023. Clinical data, laboratory test results, treatment protocols, and prognoses were collected and analyzed.

RESULTS

The study population included 146 patients with MHD, 93 (63.7%) of whom were infected with SARS-CoV-2. The number of non-severe, severe, and critical cases was 84 (90.3%), 4 (4.3%), and 5 (5.3%), respectively. Six patients (6.5%) died during the study period. The main symptoms of SARS-CoV-2 infection, including fever, cough, and fatigue, were less common in patients with MHD than the controls. During SARS-CoV-2 infection, the C-reactive protein (2.9 vs. 11.8 mg/dl, p < 0.0001) and ferritin levels(257.7 vs. 537 ng/l, p < 0.0001) were elevated. The hemoglobin(113vs 111 g/L, p = 0.0001) and albumin levels(39.4 vs. 36.1 g/L, p < 0.0001) decreased. Generally, it took two months for the hemoglobin levels to recover. Positivity rate for SARS-COV-2 serum immunoglobin G (IgG) antibodies and IgG titers were lower in dialysis patients than the controls. Age was positively associated with disease severity, while age and hyponatremia were associated with death.

CONCLUSIONS

Patients with MHD and COVID-19 were primarily classified as non-severe. SARS-CoV-2 infection would soon lead to the increase of inflammation related acute response protein in dialysis patients, and then lead to the decrease of hemoglobin and albumin. About 9.6% in HD patients were severe cases and had poor prognosis. Advanced age and hyponatremia were associated with disease severity and prognosis.

Vaccine Effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 Omicron BA.2 in CKD

BACKGROUND

The ongoing coronavirus disease 2019 (COVID-19) pandemic has posed increased risks of hospitalization and mortality in patients with underlying CKD. Current data on vaccine effectiveness of COVID-19 vaccines are limited to patients with CKD on dialysis and seroconversion in the non-dialysis population.

METHODS

A case-control study was conducted of adults with CKD using data extracted from the electronic health record database in Hong Kong. Adults with CKD and COVID-19 confirmed by PCR were included in the study. Each case was matched with up to ten controls attending Hospital Authority services without a diagnosis of COVID-19 on the basis of age, sex, and index date (within three calendar days). The vaccine effectiveness of BNT162b2 and CoronaVac in preventing COVID-19 infection, hospitalizations, and all-cause mortality was estimated using conditional logistic regression adjusted by patients' comorbidities and medication history during the outbreak from January to March 2022.

RESULTS

A total of 20,570 COVID-19 cases, 6604 COVID-19-related hospitalizations, and 2267 all-cause mortality were matched to 81,092, 62,803, and 21,348 controls, respectively. Compared with the unvaccinated group, three doses of BNT162b2 or CoronaVac were associated with a reduced risk of infection (BNT162b2: 64% [95% confidence interval (CI), 60 to 67], CoronaVac: 42% [95% CI, 38 to 47]), hospitalization (BNT162b2: 82% [95% CI, 77 to 85], CoronaVac: 80% [95% CI, 76 to 84]), and mortality (BNT162b2: 94% [95% CI, 88 to 97], CoronaVac: 93% [95% CI, 88 to 96]). Vaccines were less effective in preventing infection and hospitalization in the eGFR <15 and 15-29 ml/min per 1.73 m 2 subgroups as compared with higher GFR subgroups. However, receipt of vaccine, even for one dose, was effective in preventing all-cause mortality, with estimates similar to the higher eGFR subgroups, as compared with unvaccinated.

CONCLUSIONS

A dose-response relationship was observed between the number of BNT162b2 or CoronaVac doses and the effectiveness against COVID-19 infection and related comorbidity in the CKD population.

Vaccination for Patients Receiving Dialysis

Vaccinating patients receiving dialysis may prevent morbidity and mortality in this vulnerable population. The National Forum of End-Stage Renal Disease Networks (the Forum) published a revised vaccination toolkit in 2021 to update evidence and recommendations on vaccination for patients receiving dialysis. Significant changes in the last 10 years include more data supporting the use of a high-dose influenza vaccine, the introduction of the Heplisav-B vaccine for hepatitis B, and changes in pneumococcal vaccines, including the approval of the PCV15 and PCV20 to replace the PCV13 and PPSV23 vaccines. Additional key items include the introduction of vaccines against severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19), and a new vaccine to prevent respiratory syncytial virus disease. Historically, influenza and pneumococcal vaccinations were routinely administered by dialysis facilities, and because of possible risks of hematogenous spread of hepatitis B, dialysis providers often have detailed hepatitis B vaccine protocols. In March 2021, COVID-19 vaccines were made available for dialysis facilities to administer, although with the end of the public health emergency, vaccine policies by dialysis facilities against COVID-19 remains uncertain. The respiratory syncytial virus vaccine was authorized in 2023, and how dialysis facilities will approach this vaccine also remains uncertain. This review summarizes the Forum's vaccination toolkit and discusses the role of the dialysis facility in vaccinating patients to reduce the risk of severe infections.

Two versus three doses of COVID-19 vaccine and post-vaccination COVID-19 infection in hemodialysis patients

Background and aim

Patients with chronic kidney disease including those undergoing hemodialysis (HD) constitute a particularly challenging group regarding COVID-19 vaccination. The present study aimed to compare the rate of reinfection after two and three doses of Sinopharm COVID-19 vaccine in HD patients.

Patients and methods

The study included 80 HD patients who received three doses of Sinopharm COVID-19 vaccine. In addition, there were another 80 patients who received only two doses of the vaccine. Patients in the latter group were selected based on propensity matching score with 1:1 ratio. Patients were monitored for post-vaccination COVID-19 infection using PCR examination of nasopharyngeal swabs. Patients were also monitored for post-vaccination complications including general complaints (headache, fever, fatigue), injection site complaints (arm pain, swelling, itching, rash), musculoskeletal complaints (muscle spasm or pain, joint pain) and others. All patients were followed for six months.

Results

The present study included 80 patients submitted to COVID-19 vaccination with two doses of Sinopharm vaccine (GI) and other 80 patients who received three doses of the same vaccine (GII). At the end of follow up, 11 patients (13.8 %) in GI caught COVID-19 infection. In contrast, no patient in GII had infection (P<0.001). Comparison between patients who had COVID-19 infection and those without infection revealed that the former subgroup had significantly lower BMI (23.3 ± 2.3 versus 27.5 ± 8.1 Kg/m2), higher frequency of associated Hepatitis C (HCV) infection (54.6 % versus 2.9 %, P<0.001) and higher serum ferritin levels [median (IQR): 1101.0 (836.0-1564.0) versus 675.0 (467.0-767.7) ng/mL, P=0.01]. Binary logistic regression analysis identified high serum ferritin levels [OR (95% CI): 0.014 (0.001-0.15), P<0.001] and associated HCV infection [OR (95% CI): 0.99 (0.98-1.01), P=0.02] as significant predictors of post-vaccination COVID-19 infection in multivariate analysis.

Conclusions

A three dose regime of Sinopharm COVID-19 vaccine associated with significantly lower rate of reinfection COVID-19 infection in HD patients. Infected patients had significantly lower BMI, higher frequency of HCV and higher ferritin levels.

BNT162b2 versus mRNA-1273 Third Dose COVID-19 Vaccine in Patients with CKD and Maintenance Dialysis Patients

BACKGROUND

There is a lack of randomized controlled trial data regarding differences in immunogenicity of varying coronavirus disease 2019 (COVID-19) mRNA vaccine regimens in CKD populations.

METHODS

We conducted a randomized controlled trial at three kidney centers in Toronto, Ontario, Canada, evaluating the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody response after third dose vaccination. Participants ( n =273) with CKD not on dialysis or receiving dialysis were randomized 1:1 to third dose 30- µ g BNT162b2 (Pfizer-BioNTech) or 100- µ g mRNA-1273 (Moderna). The primary outcome of this study was SARS-CoV-2 IgG-binding antibodies to the receptor-binding domain (anti-RBD). Spike protein (antispike), nucleocapsid protein, and vaccine reactogenicity were also evaluated. Serology was measured before third dose and 1, 3, and 6 months after third dose. A subset of participants ( n =100) were randomly selected to assess viral pseudovirus neutralization against wild-type D614G, B.1.617.2 (Delta), and B.1.1.529 (Omicron BA.1).

RESULTS

Among 273 participants randomized, 94% were receiving maintenance dialysis and 59% received BNT162b2 for initial two dose COVID-19 vaccination. Third dose of mRNA-1273 was associated with higher mean anti-RBD levels (1871 binding antibody units [BAU]/ml; 95% confidence interval [CI], 829 to 2988) over a 6-month period in comparison with third dose BNT162b2 (1332 BAU/ml; 95% CI, 367 to 2402) with a difference of 539 BAU/ml (95% CI, 139 to 910; P = 0.009). Neither antispike levels nor neutralizing antibodies to wild-type, Delta, and Omicron BA.1 pseudoviruses were statistically different. COVID-19 infection occurred in 10% of participants: 15 (11%) receiving mRNA-1273 and 11 (8%) receiving BNT162b2. Third dose BNT162b2 was not associated with a significant different risk for COVID-19 in comparison with mRNA-1273 (hazard ratio, 0.78; 95% CI, 0.27 to 2.2; P = 0.63).

CONCLUSIONS

In patients with CKD, third dose COVID-19 mRNA vaccination with mRNA-1273 elicited higher SARS-CoV-2 anti-RBD levels in comparison with BNT162b2 over a 6-month period.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

COVID-19 Vaccine Boosters in Patients With CKD (BOOST KIDNEY), NCT05022329 .

Measures to Increase Immunogenicity of SARS-CoV-2 Vaccines in Solid Organ Transplant Recipients: A Narrative Review

Purpose of review: To review the data on the immunogenicity of COVID-19 vaccines, administered by different strategies, in solid organ transplant recipients (SOTRs). Recent findings: COVID-19 booster vaccines were given to SOTRs as a widespread practice in many transplant centers, mostly as the third and/or fourth dose in an extended vaccine series, with a significantly improved humoral response compared with the initial two-dose scheme. However, one-third of SOTRs remained unresponsive, despite these boosters. Next steps: Vaccination with standard dosing remains the most feasible strategy for attaining protection against COVID-19. Additional booster doses and temporarily holding or reducing mycophenolate mofetil/mycophenolic acid may provide immunogenicity to vaccines, according to recent studies demonstrating some efficacy with these measures. Preexposure prophylaxis with monoclonal antibodies showed benefit in immunocompromised patients but is no longer recommended by the National Institutes of Health (NIH) due to diminished efficacy against Omicron and recent variants. Screening for the presence and titers of SARS-CoV-2-specific antibodies in SOTRs is not recommended in most clinical settings. T cell-based techniques are needed to evaluate vaccine efficacy and risk of infection. As SARS-CoV-2 continues to evolve, new vaccines based on conservative protein component/complexes of the COVID virus, in addition to its spike protein, are warranted to offer prolonged protection.

"Flying a plane and building it at the same time": Lessons learned from the dynamic implementation of mass vaccination clinics in the Region of Waterloo, Ontario, Canada

BACKGROUND

Vaccination plays a critical role during pandemics, and mass vaccination clinics are often an imperative public health measure. These clinics usually consist of multi-disciplinary teams, which can pose significant coordination challenges, yet also present an opportunity for collectively contributing towards mitigating the impact of infection within communities. This study explores the coordination dynamics of the Region of Waterloo's coronavirus disease of 2019 (COVID-19) mass vaccination clinics in Ontario, Canada, between July 2021 and April 2022.

METHODS

This qualitative study included 16 purposively selected participants working in mass vaccination clinics. Participants were individually interviewed for 40-60 min. An inductive and iterative thematic analysis was undertaken, including open coding, grouping, labelling, regrouping and making sense of the themes.

RESULTS

Three interrelated themes were created: (1) unpredictable work environment, which was comprised of changing clinic processes and the impact of clinic adjustments to the running of the clinics; (2) clinic cohesion challenges, which included staff role disparities, limited job preparation and clinic system silos; and (3) adaptable and supportive work environment, which was comprised of staff adaptability, dispositional flexibility and a supportive work environment. While the first two themes created a precarious situation in the clinics, the third countered it, leading to a largely successful clinic implementation.

CONCLUSIONS

The rapid evolution and high transmissibility of COVID-19 in communities required a public health response that felt like flying and building a plane simultaneously - a seemingly impossible yet necessary task. However, an adaptable and supportive work environment was critical for establishing an atmosphere that can overcome challenges from a constantly changing pandemic and the guidance of public health officials. Such lessons gained from understanding the dynamic experiences in mass vaccination clinics are essential for improving the development and operation of future immunization campaigns.

Response to Immunization against SARS-CoV-2 and Risk of Omicron Infection in Dialysis Patients: A Prospective Cohort Study

It is not well established to what extent previous immunizations offer protection against infections with the SARS-CoV-2 Omicron variant in dialysis patients. We aimed to define the relevant humoral response in dialysis patients using a SARS-CoV-2 IgG chemiluminescence microparticle immunoassay (CMIA) compared to the activity of neutralizing antibodies assessed by a virus neutralization test. Next, we aimed to determine differences in humoral and cellular response levels over time among patients infected or not infected by the Omicron variant of SARS-CoV-2. Immunological parameters of cellular and humoral response to SARS-CoV-2 were analyzed at baseline and after 3 (T3), 6 (T6) and 14 months (T14). In this monocentric cohort study, we followed 110 dialysis patients (mean age 68.4 ± 13.7 years, 60.9% male) for a median of 545 days. We determined an anti-SARS-CoV-2 IgG level of 56.7 BAU/mL as an ideal cut-off value with a J-index of 90.7. Patients infected during the Omicron era had significantly lower (p < 0.001) mean antibody levels at T0 (3.5 vs. 111.2 BAU/mL), T3 (269.8 vs. 699.8 BAU/mL) and T6 (260.2 vs. 513.9 BAU/mL) than patients without Omicron infection. Patients who developed higher antibody levels at the time of the basic immunizations were less likely to become infected with SARS-CoV-2 during the Omicron era. There is a need to adjust the cut-off values for anti-SARS-CoV-2 IgG levels in dialysis patients.

Immunogenic proteins and potential delivery platforms for mpox virus vaccine development: A rapid review

Since May 2022, the mpox virus (MPXV) has spread worldwide and become a potential threat to global public health. Vaccines are important tools for preventing MPXV transmission and infection in the population. However, there are still no available potent and applicable vaccines specifically for MPXV. Herein, we highlight several potential vaccine targets for MPVX and emphasize potent immunogens, such as M1R, E8L, H3L, A29L, A35R, and B6R proteins. These proteins can be integrated into diverse vaccine platforms to elicit powerful B-cell and T-cell responses, thereby providing protective immunity against MPXV infection. Overall, research on the MPXV vaccine targets would provide valuable information for developing timely effective MPXV-specific vaccines.

COVID-19 Vaccine Effectiveness Among Patients With Maintenance Dialysis; Observations From Population Level Cohort Studies in 2 Large Canadian Provinces

Background

It was unknown if the effectiveness of COVID-19 vaccines could vary between regions.

Objective

To explore key differences in COVID-19 pandemics in British Columbia (BC) and Ontario (ON) and to investigate if the vaccine effectiveness (VE) among maintenance dialysis population could vary between these 2 provinces.

Study Design

Retrospective cohort.

Setting and Patients

This retrospective cohort study included patients from population-level registry in BC who were on maintenance dialysis from December 14, 2020, to December 31, 2021. The COVID-19 VE among BC patients were compared to the previously published VE among similar patient population in ON. Two-sample t-test for unpaired data were used to investigate if the VE estimates from BC and ON were statistically significantly different.

Exposure

Exposure to COVID-19 vaccines (BNT162b2, ChAdOx1nCoV-19, mRNA-1273) was modeled in a time-dependent fashion.

Outcome

Reverse transcription polymerase chain reaction (RT-PCR) confirmed COVID-19 infection and related severe outcome defined by hospitalization or death.

Analytical Approach

Time-dependent Cox regression analysis.

Results

This study using BC data included 4284 patients. Median age was 70 years and 61% was male. Median follow-up time was 382 days. 164 patients developed COVID-19 infection. The ON study by Oliver et al included 13 759 patients with a mean age of 68 years. 61% of the study sample was male. Median follow-up time for patients in the ON study was 102 days. A total of 663 patients developed COVID-19 infection. During the overlapped study periods, BC had 1 pandemic wave compared to 2 in Ontario with substantially higher infection rates. Vaccination timing and roll out among the study population were substantially different. Median time between first and second dose was 77 days (interquartile range [IQR] 66-91) in BC compared to 39 days (IQR = 28-56) in Ontario. Distribution of COVID-19 variants during the study period appeared to be similar. In BC, compared to pre-vaccination person-time, risk of developing COVID-19 infection was 64% (aHR [95% CI] 0.36 [0.21, 0.63]), 80% (0.20 [0.12, 0.35]) and 87% (0.13 [0.06, 0.29]) less when exposed to 1 dose, 2 doses, and 3 doses, respectively. In contrast, risk reduction among Ontario patients was 41% (0.59 [0.46, 0.76]) and 69% (0.31 [0.22, 0.42]) for 1 dose and 2 doses, respectively (patients did not receive the third dose by study end date of June 30, 2021). VE against COVID-19 infection in BC and ON was not statistically significantly different, the P values for exposure to 1 dose and 2 doses comparisons were 0.103 and 0.163, respectively. Similarly, in BC, risk of developing COVID-19-related hospitalization or death were 54% (0.46 [0.24, 0.90]), 75% (0.25 [0.13, 0.48]) and 86% (0.14 [0.06, 0.34]) less for 1 dose, 2 doses, and 3 doses, respectively. Interestingly, exposure to second dose appeared to provide better protection against severe outcomes in Ontario versus BC, risk reduction was 83% (aHR = 0.17, 95% CI [0.10, 0.30]) and 75% (aHR = 0.25, 95% CI [0.13, 0.48]), respectively. However, the adjusted hazard ratios were not statistically significantly different between BC and ON, the P values were 0.676 and 0.369 for exposure to 1 dose and 2 doses, respectively.

Limitations

Infection rate, variant distribution, and vaccination strategies were compared using publicly available data. VE estimates were compared from 2 independent cohort studies from 2 provinces without patient-level data sharing.

Conclusions

Health Canada approved COVID-19 vaccines were highly effective among patients with maintenance dialysis from BC and ON. Although there appeared to be between province differences in pandemic waves and vaccination strategies, the VE against COVID-19 infection as well as related severe outcome appeared to be not statistically significantly different. A nationally representative VE could be estimated using pooled data from multiple regions.

Coping Strategies for Pertussis Resurgence

Pertussis (whooping cough) is a respiratory disease caused primarily by Bordetella pertussis, a Gram-negative bacteria. Pertussis is a relatively contagious infectious disease in people of all ages, mainly affecting newborns and infants under 2 months of age. Pertussis is undergoing a resurgence despite decades of high rates of vaccination. To better cope with the challenge of pertussis resurgence, we evaluated its possible causes and potential countermeasures in the narrative review. Expanded vaccination coverage, optimized vaccination strategies, and the development of a new pertussis vaccine may contribute to the control of pertussis.