Spatial and temporal fluctuations in COVID-19 fatality rates in Brazilian hospitals

SARS-CoV-2 reinfection rate before and after VOC Omicron emergence: a retrospective study in Brazil

SARS-COV-2 reinfection has been reported worldwide, although its rate remains unclear. VOC Omicron's emergence and its sub-variants led to an unprecedented number of COVID-19 cases in several countries, raising concerns regarding reinfection rates. 324,979 RT-qPCR-confirmed positive cases (72.57% from Minas Gerais State) diagnosed between April 1, 2020, and August 31, 2022, at the Hermes Pardini, Grupo Fleury (Brazil) were used to estimate the reinfection rate. Instances of reinfection were characterized by two positive tests occurring with a minimum interval of 60 days. We identified 11,669 cases of reinfection. The states of Minas Gerais, São Paulo, Rio de Janeiro and Goiás represented almost 41% of the reinfections. Up until epidemiological week 46 of 2020, only 14 cases of reinfection were recorded. The majority of reinfections, totalling 6,316 cases, were detected during the circulation period of the Omicron and its sublineages BA.1 and BA.2. Another 4,273 reinfections occurred during the circulation period of sublineages BA.4 and BA.5, revealing two distinct groups of observations. The first group comprised cases of reinfection with a shorter time interval (two infections within a period of up to 200 days), while the second group was associated with a longer time interval (two infections within a period of more than 500 days). The reinfection rate during this period was nearly 8%, which is six times higher than the rate observed at the beginning of the study. In conclusion, our study underscores the dynamic nature of SARS-CoV-2 reinfections and their correlation with emerging variants such as Omicron.

Spatiotemporal transmission of SARS-CoV-2 lineages during 2020-2021 in Pernambuco-Brazil

SARS-CoV-2 virus emerged as a new threat to humans and spread around the world, leaving a large death toll. As of January 2023, Brazil is among the countries with the highest number of registered deaths. Nonpharmacological and pharmacological interventions have been heterogeneously implemented in the country, which, associated with large socioeconomic differences between the country regions, has led to distinct virus spread dynamics. Here, we investigate the spatiotemporal dispersion of SARS-CoV-2 lineages in the Pernambuco state (Northeast Brazil) throughout the distinct epidemiological scenarios that unfolded in the first 2 years of the pandemic. We generated a total of 1,389 new SARS-CoV-2 genomes from June 2020 to August 2021. This sampling captured the arrival, communitary transmission, and the circulation of the B1.1, B.1.1.28, and B.1.1.33 lineages; the emergence of the former variant of interest P.2; and the emergence and fast replacement of all previous variants by the more transmissible variant of concern P.1 (Gamma). Based on the incidence and lineage spread pattern, we observed an East-to-West to inner state pattern of transmission, which is in agreement with the transmission of more populous metropolitan areas to medium- and small-size country-side cities in the state. Such transmission patterns may be partially explained by the main routes of traffic across municipalities in the state. Our results highlight that the fine-grained intrastate analysis of lineages and incidence spread can provide actionable insights for planning future nonpharmacological intervention for air-borne transmissible human pathogens.IMPORTANCEDuring the COVID-19 pandemic, Brazil was one of the most affected countries, mainly due its continental-size, socioeconomic differences among regions, and heterogeneous implementation of intervention methods. In order to investigate SARS-CoV-2 dynamics in the state of Pernambuco, we conducted a spatiotemporal dispersion study, covering the period from June 2020 to August 2021, to comprehend the dynamics of viral transmission during the first 2 years of the pandemic. Throughout this study, we were able to track three significant epidemiological waves of transmission caused by B1.1, B.1.1.28, B.1.1.33, P.2, and P.1 lineages. These analyses provided valuable insights into the evolution of the epidemiological landscape, contributing to a deeper understanding of the dynamics of virus transmission during the early years of the pandemic in the state of Pernambuco.

The unequal impact of the pandemic at subnational levels and educational attainment-related inequalities in COVID-19 mortality, Brazil, 2020-2021

OBJECTIVES

We estimated COVID-19 mortality indicators in 2020-2021 to show the epidemic's impact at subnational levels and to analyze educational attainment-related inequalities in COVID-19 mortality in Brazil.

STUDY DESIGN

This was an ecological study with secondary mortality information.

METHODS

Crude and age-standardized COVID-19 mortality rates were calculated by gender, major regions, and states. The COVID-19 proportional mortality (percentage) was estimated by gender and age in each region. Measures of education-related inequalities in COVID-19 mortality were calculated per state, in each of which the COVID-19 maternal mortality rate (MMR) was estimated by the number of COVID-19 maternal deaths per 100,000 live births (LBs).

RESULTS

The analysis of mortality rates at subnational levels showed critical regional differences. The North region proved to be the most affected by the pandemic, followed by the Center-West, with age-standardized COVID-19 mortality rates above 2 per 1000 inhabitants. The peak of COVID-19 mortality occurred in mid-March/April 2021 in all regions. Great inequality by educational level was found, with the illiterate population being the most negatively impacted in all states. The proportional mortality showed that males and females aged 50-69 years were the most affected. The MMR reached critical values (>100/100,000 LB) in several states of the North, Northeast, Southeast, and Center-West regions.

CONCLUSIONS

This study highlights stark regional and educational disparities in COVID-19 mortality in Brazil. Exacerbated by the pandemic, these inequalities reveal potential areas for intervention to reduce disparities. The results also revealed high MMRs in certain states, underscoring pre-existing healthcare access challenges that worsened during the pandemic.

Enhancing the epidemiological surveillance of SARS-CoV-2 using Sanger sequencing to identify circulating variants and recombinants

Since the emergence of SARS-CoV-2 in December 2019, more than 12,000 mutations in the virus have been identified. These could cause changes in viral characteristics and directly impact global public health. The emergence of variants is a great concern due to the chance of increased transmissibility and infectivity. Sequencing for surveillance and monitoring circulating strains is extremely necessary as the early identification of new variants allows public health agencies to make faster and more effective decisions to contain the spread of the virus. In the present study, we identified circulating variants in samples collected in Belo Horizonte, Brazil, and detected a recombinant lineage using the Sanger method. The identification of lineages was done through gene amplification of SARS-CoV-2 by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). By using these specific fragments, we were able to differentiate one variant of interest and five circulating variants of concern. We were also able to detect recombinants. Randomly selected samples were sequenced by either Sanger or Next Generation Sequencing (NGS). Our findings validate the effectiveness of Sanger sequencing as a powerful tool for monitoring variants. It is easy to perform and allows the analysis of a larger number of samples in countries that cannot afford NGS.

Temporal trends of severity and outcomes of critically ill patients with COVID-19 after the emergence of variants of concern: A comparison of two waves

BACKGROUND

The emergence of SARS-CoV-2 variants led to subsequent waves of COVID-19 worldwide. In many countries, the second wave of COVID-19 was marked by record deaths, raising the concern that variants associated with that wave might be more deadly. Our aim was to compare outcomes of critically-ill patients of the first two waves of COVID-19.

METHODS

This retrospective cohort included critically-ill patients admitted between March-June 2020 and April-July 2021 in the largest academic hospital in Brazil, which has free-access universal health care system. We compared admission characteristics and hospital outcomes. The main outcome was 60-day survival and we built multivariable Cox model based on a conceptual causal diagram in the format of directed acyclic graph (DAG).

RESULTS

We included 1583 patients (1315 in the first and 268 in the second wave). Patients in the second wave were younger, had lower severity scores, used prone and non-invasive ventilatory support more often, and fewer patients required mechanical ventilation (70% vs 80%, p<0.001), vasopressors (60 vs 74%, p<0.001), and dialysis (22% vs 37%, p<0.001). Survival was higher in the second wave (HR 0.61, 95%CI 0.50-0.76). In the multivariable model, admission during the second wave, adjusted for age, SAPS3 and vaccination, was not associated with survival (aHR 0.85, 95%CI 0.65-1.12).

CONCLUSIONS

In this cohort study, patients with COVID-19 admitted to the ICU in the second wave were younger and had better prognostic scores. Adjusted survival was similar in the two waves, contrasting with record number of hospitalizations, daily deaths and health system collapse seen across the country in the second wave. Our findings suggest that the combination of the burden of severe cases and factors such as resource allocation and health disparities may have had an impact in the excess mortality found in many countries in the second wave.

Access to health and social protection policies by homeless people during the COVID-19 pandemic: a mixed-methods case study on tailored inter-sector care during a health emergency

Introduction

The article analyzed homeless people's (HP) access to health and social protection policies and tailored inter-sector care, including emergency measures, during the COVID-19 pandemic in Belo Horizonte (BH), capital of Minas Gerais state, Brazil. It intended to provide data on HP and evaluate existing public policies focused on vulnerable populations during this health emergency.

Methods

The study adopted a mixed-methods design with triangulation of quantitative and qualitative data.

Results

Social cartography showed that in the early months of the pandemic, the health administration had difficulty reordering the health system, which experienced constant updates in the protocols but was nevertheless consolidated over the months. The evidence collected in the study showed that important emergency interventions in the municipality of BH involved activities that facilitated access by HP to the supply of services.

Discussion

The existence of national guidelines for inter-sector care for HP cannot be ruled out as a positive influence, although the municipalities are responsible for their implementation. Significantly, a health emergency was necessary to intensify the relationship between health and social protection services. Roving services were among those with the greatest positive evidence, with the least need for infrastructure to be replicated at the local level. In addition, the temporary supply of various inter-sector services, simultaneously with the provision of day shelters by organized civil society, was considered a key factor for expanding and intensifying networks of care for HP during the emergency phase. A plan exists to continue and expand this model in the future. The study concluded that understanding the inter-sector variables that impact HP contributes to better targeting of investments in interventions that work at the root causes of these issues or that increase the effectiveness of health and social protection systems.

Risk factors for long coronavirus disease 2019 (long COVID) among healthcare personnel, Brazil, 2020-2022

OBJECTIVE

To determine risk factors for the development of long coronavirus disease 2019 (COVID-19) in healthcare personnel (HCP).

METHODS

We conducted a case-control study among HCP who had confirmed symptomatic COVID-19 working in a Brazilian healthcare system between March 1, 2020, and July 15, 2022. Cases were defined as those having long COVID according to the Centers for Disease Control and Prevention definition. Controls were defined as HCP who had documented COVID-19 but did not develop long COVID. Multiple logistic regression was used to assess the association between exposure variables and long COVID during 180 days of follow-up.

RESULTS

Of 7,051 HCP diagnosed with COVID-19, 1,933 (27.4%) who developed long COVID were compared to 5,118 (72.6%) who did not. The majority of those with long COVID (51.8%) had 3 or more symptoms. Factors associated with the development of long COVID were female sex (OR, 1.21; 95% CI, 1.05-1.39), age (OR, 1.01; 95% CI, 1.00-1.02), and 2 or more SARS-CoV-2 infections (OR, 1.27; 95% CI, 1.07-1.50). Those infected with the SARS-CoV-2 δ (delta) variant (OR, 0.30; 95% CI, 0.17-0.50) or the SARS-CoV-2 o (omicron) variant (OR, 0.49; 95% CI, 0.30-0.78), and those receiving 4 COVID-19 vaccine doses prior to infection (OR, 0.05; 95% CI, 0.01-0.19) were significantly less likely to develop long COVID.

CONCLUSIONS

Long COVID can be prevalent among HCP. Acquiring >1 SARS-CoV-2 infection was a major risk factor for long COVID, while maintenance of immunity via vaccination was highly protective.

COVID-19 and health systems in Brazil and around the world: effects on the working conditions and health of health workers

This article discusses the impacts of the COVID-19 pandemic on health systems and its effects on the working conditions and mental health of health professionals and invisible health workers. It presents data on deaths among health professionals, highlighting the need for better and safer working conditions and improvements in public management. We emphasize WHO/PAHO recommendations and the need for equitable vaccine distribution, including poor countries and vulnerable populations. We also highlight the impacts of interrupting essential health services, such as the treatment of chronic conditions and infectious disease prevention, and the damage caused by the dissemination of fake news, stressing the need to improve access to correct and safe health information.

Epidemiological drivers of transmissibility and severity of SARS-CoV-2 in England

As the SARS-CoV-2 pandemic progressed, distinct variants emerged and dominated in England. These variants, Wildtype, Alpha, Delta, and Omicron were characterized by variations in transmissibility and severity. We used a robust mathematical model and Bayesian inference framework to analyse epidemiological surveillance data from England. We quantified the impact of non-pharmaceutical interventions (NPIs), therapeutics, and vaccination on virus transmission and severity. Each successive variant had a higher intrinsic transmissibility. Omicron (BA.1) had the highest basic reproduction number at 8.3 (95% credible interval (CrI) 7.7-8.8). Varying levels of NPIs were crucial in controlling virus transmission until population immunity accumulated. Immune escape properties of Omicron decreased effective levels of immunity in the population by a third. Furthermore, in contrast to previous studies, we found Alpha had the highest basic infection fatality ratio (2.9%, 95% CrI 2.7-3.2), followed by Delta (2.2%, 95% CrI 2.0-2.4), Wildtype (1.2%, 95% CrI 1.1-1.2), and Omicron (0.7%, 95% CrI 0.6-0.8). Our findings highlight the importance of continued surveillance. Long-term strategies for monitoring and maintaining effective immunity against SARS-CoV-2 are critical to inform the role of NPIs to effectively manage future variants with potentially higher intrinsic transmissibility and severe outcomes.

Complexity in Epidemiology and Public Health. Addressing Complex Health Problems Through a Mix of Epidemiologic Methods and Data

Public health and the underlying disease processes are complex, often involving the interaction of biologic, social, psychologic, economic, and other processes that may be nonlinear and adaptive and have other features of complex systems. There is therefore a need to push the boundaries of public health beyond single-factor data analysis and expand the capacity of research methodology to tackle real-world complexities. This article sets out a way to operationalize complex systems thinking in public health, with a particular focus on how epidemiologic methods and data can contribute towards this end. Our proposed framework comprises three core dimensions-patterns, mechanisms, and dynamics-along which complex systems may be conceptualized. These dimensions cover seven key features of complex systems-emergence, interactions, nonlinearity, interference, feedback loops, adaptation, and evolution. We relate this framework to examples of methods and data traditionally used in epidemiology. We conclude that systematic production of knowledge on complex health issues may benefit from: formulation of research questions and programs in terms of the core dimensions we identify, as a comprehensive way to capture crucial features of complex systems; integration of traditional epidemiologic methods with systems methodology such as computational simulation modeling; interdisciplinary work; and continued investment in a wide range of data types. We believe that the proposed framework can support the systematic production of knowledge on complex health problems, with the use of epidemiology and other disciplines. This will help us understand emergent health phenomena, identify vulnerable population groups, and detect leverage points for promoting public health.

Cost Effectiveness of Strategies for Caring for Critically Ill Patients with COVID-19 in Tanzania

BACKGROUND

The resources for critical care are limited in many settings, exacerbating the significant morbidity and mortality associated with critical illness. Budget constraints can lead to choices between investing in advanced critical care (e.g. mechanical ventilators in intensive care units) or more basic critical care such as Essential Emergency and Critical Care (EECC; e.g. vital signs monitoring, oxygen therapy, and intravenous fluids).

METHODS

We investigated the cost effectiveness of providing EECC and advanced critical care in Tanzania in comparison with providing 'no critical care' or 'district hospital-level critical care' using coronavirus disease 2019 (COVID-19) as a tracer condition. We developed an open-source Markov model ( https://github.com/EECCnetwork/POETIC_CEA ) to estimate costs and disability-adjusted life-years (DALYs) averted, using a provider perspective, a 28-day time horizon, patient outcomes obtained from an elicitation method involving a seven-member expert group, a normative costing study, and published literature. We performed a univariate and probabilistic sensitivity analysis to assess the robustness of our results.

, RESULTS

EECC is cost effective 94% and 99% of the time when compared with no critical care (incremental cost-effectiveness ratio [ICER] $37 [-$9 to $790] per DALY averted) and district hospital-level critical care (ICER $14 [-$200 to $263] per DALY averted), respectively, relative to the lowest identified estimate of the willingness-to-pay threshold for Tanzania ($101 per DALY averted). Advanced critical care is cost effective 27% and 40% of the time, when compared with the no critical care or district hospital-level critical care scenarios, respectively.

CONCLUSION

For settings where there is limited or no critical care delivery, implementation of EECC could be a highly cost-effective investment. It could reduce mortality and morbidity for critically ill COVID-19 patients, and its cost effectiveness falls within the range considered 'highly cost effective'. Further research is needed to explore the potential of EECC to generate even greater benefits and value for money when patients with diagnoses other than COVID-19 are accounted for.

Covid-19 school closures negatively impacted elementary-school students' reading comprehension and reading fluency skills

In Brazil, schools remained closed to prevent the spread of COVID-19 for approximately two years. In this study, we investigated how COVID-19 school closures were associated with gaps and losses in Brazilian students' reading skills. We contrasted the reading comprehension and fluency of 2nd- to 4th-graders in 2022 with a 2019 cohort. Furthermore, we investigated how 2022 5th graders' reading comprehension and fluency skills have improved since 2019. Overall, results showed that COVID-19 school closures were associated with gaps but not losses in reading comprehension and fluency. Therefore, these skills should be targets of educational interventions.

Antigen-Specific Antibody Signature Is Associated with COVID-19 Outcome

Numerous studies have focused on inflammation-related markers to understand COVID-19. In this study, we performed a comparative analysis of spike (S) and nucleocapsid (N) protein-specific IgA, total IgG and IgG subclass response in COVID-19 patients and compared this to their disease outcome. We observed that the SARS-CoV-2 infection elicits a robust IgA and IgG response against the N-terminal (N1) and C-terminal (N3) region of the N protein, whereas we failed to detect IgA antibodies and observed a weak IgG response against the disordered linker region (N2) in COVID-19 patients. N and S protein-specific IgG1, IgG2 and IgG3 response was significantly elevated in hospitalized patients with severe disease compared to outpatients with non-severe disease. IgA and total IgG antibody reactivity gradually increased after the first week of symptoms. Magnitude of RBD-ACE2 blocking antibodies identified in a competitive assay and neutralizing antibodies detected by PRNT assay correlated with disease severity. Generally, the IgA and total IgG response between the discharged and deceased COVID-19 patients was similar. However, significant differences in the ratio of IgG subclass antibodies were observed between discharged and deceased patients, especially towards the disordered linker region of the N protein. Overall, SARS-CoV-2 infection is linked to an elevated blood antibody response in severe patients compared to non-severe patients. Monitoring of antigen-specific serological response could be an important tool to accompany disease progression and improve outcomes.

Clinical Characteristics and Outcomes among Vaccinated and Unvaccinated Patients with Cardiovascular Disease Who Were Hospitalized for COVID-19 in Brazil: Retrospective Cohort

INTRODUCTION

COVID-19 in Brazil has already caused, and it still causes, several impacts on health, economy, and education. The risk factors for death involved those with cardiovascular diseases (CVD), which were prioritized for the vaccination of COVID-19.

OBJECTIVE

To investigate the clinical characteristics and outcomes between vaccinated and unvaccinated patients with cardiovascular diseases hospitalized for COVID-19 in Brazil in the year 2022.

METHODS

A retrospective cohort was analyzed from the year 2022, with cases being hospitalized by COVID-19 being drawn from SIVEP-GRIPE surveillance. We compared clinical characteristics, comorbidities, and outcomes between CVD carriers and non-carriers, and we also compared vaccinated with two doses vs. those that are unvaccinated in CVD carriers. We performed chi-square, odds ratio, logistic regression, and survival analysis.

RESULTS

We included, in the cohort, 112,459 hospital inpatients. An amount of 71,661 (63.72%) of the hospitalized patients had CVD. Regarding deaths, 37,888 (33.69%) died. Regarding vaccination against COVID-19, 20,855 (18.54%) people were not vaccinated with any dose among those with CVD. Death p- < 0.001 (OR 1.307-CI 1.235-1.383) and fever p- < 0.001 (OR 1.156-CI 1.098-1.218) were associated with the unvaccinated CVD carriers, and diarrhea p-0.015 (OR 1.116-CI 1.022-1.218), dyspnea p-0.022 (OR 1.074-CI 1.011-1.142), and respiratory distress p-0.021 (OR 1.070-CI 1.011-1.134) were also recorded. Those patients who possessed predictors of death, including invasive ventilation (p- < 0.001 (OR 8.816-CI 8.313-9.350)), were admitted to the ICU p- < 0.001 (OR 1.754-CI 1.684-1.827), and some had respiratory distress p- < 0.001 (OR 1.367-CI 1.312-1.423), dyspnea p < 0.001 (OR 1.341-CI 1.284-1.400), O₂ saturation < 95% p- < 0. 001 (OR 1.307-CI 1.254-1.363), they were unvaccinated against COVID-19 p- < 0.001 (OR 1.258-CI 1.200-1.319), they were of male sex p- < 0.001 (OR 1.179-CI 1.138-1.221), they had diarrhea p-0.018 (OR 1.081-CI 1.013-1.154), and they may have been old p < 0.001 (OR 1.034-CI 1.033-1.035). Survival was shorter for the unvaccinated p-0.003, and p- <0.001.

CONCLUSIONS

We highlight the predictors of death for those unvaccinated against COVID-19 in this research, and we evidenced the benefits of the COVID-19 vaccine in reducing deaths in hospitalized CVD patients.

COVID-19 mortality in Brazil, 2020-21: consequences of the pandemic inadequate management

BACKGROUND

The COVID-19 pandemic brought countless challenges to public health and highlighted the Brazilian health system vulnerabilities in facing the emergency. In this article, we analyze data on COVID-19-related deaths in 2020-21 to show the epidemic consequences in Brazil.

METHODS

The Mortality Information System and the Live Birth Information System were the primary information sources. We used population estimates in 2020-21 to calculate COVID-19 specific mortality rates by age, sex, and educational level. Considering the total number of COVID-19 deaths in 2020-21, the COVID-19 proportional mortality (%) was estimated for each age group and sex. A graph of the daily number of deaths from January 2020 to December 2021 by sex was elaborated to show the temporal evolution of COVID-19 deaths in Brazil. In addition, four indicators related to COVID-19 mortality were estimated: infant mortality rate (IMR); maternal mortality ratio (MMR); number and rate of orphans due to mother's COVID-19 death; the average number of years lost.

RESULTS

The overall COVID-19 mortality rate was 14.8 (/10,000). The mortality rates increase with age and show a decreasing gradient with higher schooling. The rate among illiterate people was 38.8/10,000, three times higher than a college education. Male mortality was 31% higher than female mortality. COVID-19 deaths represented 19.1% of all deaths, with the highest proportions in the age group of 40-59 years. The average number of years lost due to COVID-19 was 19 years. The MMR due to COVID-19 was 35.7 per 100,000 live births (LB), representing 37.4% of the overall MMR. Regarding the number of orphans due to COVID-19, we estimated that 40,830 children under 18 lost their mothers during the epidemic, with an orphans' rate of 7.5/10,000 children aged 0-17 years. The IMR was 11.7 per 1000 LB, with 0.2 caused by COVID-19. The peak of COVID-19 deaths occurred in March 2021, reaching almost 4000 COVID-19 deaths per day, higher than the average number of deaths per day from all causes in 2019.

CONCLUSIONS

The delay in adopting public health measures necessary to control the epidemic has exacerbated the spread of the disease, resulting in several avoidable deaths.

Monitoring the Establishment of VOC Gamma in Minas Gerais, Brazil: A Retrospective Epidemiological and Genomic Surveillance Study

Since its first identification in Brazil, the variant of concern (VOC) Gamma has been associated with increased infection and transmission rates, hospitalizations, and deaths. Minas Gerais (MG), the second-largest populated Brazilian state with more than 20 million inhabitants, observed a peak of cases and deaths in March-April 2021. We conducted a surveillance study in 1240 COVID-19-positive samples from 305 municipalities distributed across MG's 28 Regional Health Units (RHU) between 1 March to 27 April 2021. The most common variant was the VOC Gamma (71.2%), followed by the variant of interest (VOI) zeta (12.4%) and VOC alpha (9.6%). Although the predominance of Gamma was found in most of the RHUs, clusters of Zeta and Alpha variants were observed. One Alpha-clustered RHU has a history of high human mobility from countries with Alpha predominance. Other less frequent lineages, such as P.4, P.5, and P.7, were also identified. With our genomic characterization approach, we estimated the introduction of Gamma on 7 January 2021, at RHU Belo Horizonte. Differences in mortality between the Zeta, Gamma and Alpha variants were not observed. We reinforce the importance of vaccination programs to prevent severe cases and deaths during transmission peaks.

Effectiveness of COVID-19 Vaccination on Reduction of Hospitalizations and Deaths in Elderly Patients in Rio Grande do Norte, Brazil

Since the COVID-19 pandemic emerged, vaccination has been the core strategy to mitigate the spread of SARS-CoV-2 in humans. This paper analyzes the impact of COVID-19 vaccination on hospitalizations and deaths in the state of Rio Grande do Norte, Brazil. We analyzed data from 23,516 hospitalized COVID-19 patients diagnosed between April 2020 and August 2021. We excluded the data from patients hospitalized through direct occupancy, unknown outcomes, and unconfirmed COVID-19 cases, resulting in data from 12,635 patients cross-referenced with the immunization status during hospitalization. Our results indicated that administering at least one dose of the immunizers was sufficient to significantly reduce the occurrence of moderate and severe COVID-19 cases among patients under 59 years. Considering the partially or fully immunized patients, the mean age is similar between the analyzed groups, despite the occurrence of comorbidities and higher than that observed among not immunized patients. Thus, immunized patients present lower Unified Score for Prioritization (USP) levels when diagnosed with COVID-19. Our data suggest that COVID-19 vaccination significantly reduced the hospitalization and death of elderly patients (60+ years) after administration of at least one dose. Comorbidities do not change the mean age of moderate/severe COVID-19 cases and the days required for the hospitalization of these patients.