Reduction in COVID-19-related mortality over time but disparities across population subgroups

Effectiveness of COVID-19 vaccines against severe outcomes in cancer patients: Real-world evidence from self-controlled risk interval and retrospective cohort studies

BACKGROUND

The effectiveness of COVID-19 vaccines is generally reduced in cancer patients compared to the general population. However, there are only a few studies that compare the relative risk of breakthrough infections and severe COVID-19 outcomes in fully vaccinated cancer patients versus their unvaccinated counterparts.

METHODS

To assess the effectiveness of COVID-19 vaccines in cancer patients, we employed (1) a self-controlled risk interval (SCRI) design, and (2) a retrospective matched cohort design. A SCRI design was used to compare the risk of breakthrough infection in vaccinated cancer patients during the period immediately following vaccination ("control window") and the period in which immunity is achieved ("exposure windows"). The retrospective matched cohort design was used to compare the risk of severe COVID-19 outcomes between vaccinated and unvaccinated cancer patients. For both studies, data were extracted from the Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service cohort, including demographics, medical history, and vaccination records of all individuals confirmed with COVID-19. We used conditional Poisson regression to calculate the incidence rate ratio (IRR) for breakthrough infection and Cox regression to estimate the hazard ratio (HR) for severe outcomes.

RESULTS

Of 14,448 cancer patients diagnosed with COVID-19 between October 2020 and December 2021, a total of 217 and 3996 cancer patients were included in the SCRI and cohort study respectively. While the risk of breakthrough infections, measured by the incidence rate in the control and exposure windows, did not show statistically significant difference in vaccinated cancer patients (IRR=0.88, 95% CI: 0.64-1.22), the risk of severe COVID-19 outcomes was significantly lower in vaccinated cancer patients compared to those unvaccinated (HR=0.27, 95% CI: 0.22-0.34).

CONCLUSION

COVID-19 vaccines significantly reduce the risk of severe outcomes in cancer patients, though their efficacy against breakthrough infections is less evident.

Emerging anti-spike monoclonal antibodies against SARS-CoV-2

INTRODUCTION

Anti-spike monoclonal antibodies (mAbs) were previously authorized for the prevention and treatment of COVID-19 in immunocompromised patients. However, they are no longer authorized in the U.S. due to their lack of neutralizing activity against current circulating SARS-CoV-2 Omicron variants.

AREAS COVERED

We summarized the available data on emergent mAbs in the early stages of clinical development. Consistent with data on prior mAbs, these novel agents have been well tolerated and demonstrated a good safety profile in early clinical trials. Additionally, many of them have been engineered to ensure prolonged half-life and combined with other mAbs to overcome the potential for emerging resistant mutants. Interestingly, one of these agents has been evaluated using an inhaled route of administration, and another agent is being evaluated for treatment of long COVID.

EXPERT OPINION

Although the available data of novel mAbs holds promise, we anticipate that these agents will face similar challenges encountered by prior authorized agents, including the continued evolution of SARS-CoV-2 and emergence of new escape mutations. Strategies to potentially mitigate this are discussed. Based on prior successful experience, immunocompromised patients will certainly benefit from the utilization of mAbs for the prevention and treatment of COVID-19; thus, we need to design potential interventions to ensure the sustained activity of these agents.

Identifying Predominant Causes of Death Among Hospitalized COVID-19 Patients During Poland's Second and Third Waves

BACKGROUND Number of confirmed COVID-19 deaths per million population in Poland between November 2020 and May 2021 was one of the largest in Europe. This retrospective study was conducted at a single center in Poland between November 2020 and May 2021to evaluate the morbidity and mortality rates in 581 patients hospitalized with COVID-19. MATERIAL AND METHODS A retrospective single-center study was conducted in a dedicated COVID-19 hospital from November, 2020 to May, 2021. The data of 581 hospitalized patients were analyzed. Multimorbidity was assessed using the Charlson Comorbidity Index, including chronic kidney, respiratory, cardiovascular diseases, diabetes mellitus, cancer, and dementia. The observation period covered admission to the hospital for severe COVID-19 until discharge or death. Diagnosis of COVID-19 was confirmed by quantitative reverse transcription polymerase chain reaction test. Statistical analysis was carried out in the IBM SPSS Statistics program. RESULTS The mortality rate was 35% of all admitted patients. Lung damage was the cause of death in 60%, bacterial superinfection in 26%, arterial thrombosis or thromboembolism in 9%, and heart failure in 5% of patients. The chi-square test showed a significant relationship between sex and the cause of death related to COVID-19 pneumonia and bacterial ventilator-associated pneumonia (VAP). CONCLUSIONS The findings from this study supports findings from other countries that between November 2020 and May 2021, before SARS-CoV-2 vaccination programs were fully implemented and before effective medications and antiviral agents were developed, patients with severe COVID-19 had high rates of morbidity and mortality.