Risk of hospitalization and vaccine effectiveness among COVID-19 patients in the UAE during the Delta and Omicron outbreaks

Assessment of COVID-19 Vaccine Effectiveness Against SARS-CoV-2 Infection, Hospitalization and Death in Mexican Patients with Metabolic Syndrome from Northeast Mexico: A Multicenter Study

Background/Objectives: Metabolic syndrome (MetS) is a predisposing factor for severe COVID-19. The effectiveness of COVID-19 vaccines in patients with MetS has been poorly investigated. The aim of this study was to evaluate the effectiveness of COVID-19 vaccination before (BO) and after the Omicron (AO) SARS-CoV-2 variant in patients with MetS. Methods: This retrospective observational study was carried out in a total of 3194 patients with MetS and a COVID-19 PCR or rapid antigen test. The main outcomes were vaccine effectiveness against infection, hospitalization and death resulting from COVID-19. Results: BO, only two doses of BNT162b2 were effective against infection, this effectiveness was lost AO. Also, with two doses, BNT162b2, ChAdOx1 and CoronaVac were effective against hospitalization BO; however, AO, only BNT162b2 and CoronaVac were effective. Regarding death as an outcome of COVID-19, two doses of BNT162b2 were effective BO, whereas AO, BNT162b2 and CoronaVac were 100% effective. BO the presentation of a sore throat increased after two doses of COVID-19 vaccine regardless of the type, and the presentation of dyspnea diminished after two doses of BNT162b2 and CoronaVac. Conclusions: The SARS-CoV-2 Omicron variant has impacted vaccines' effectiveness against hospitalization and death in patients with MetS. A tailored vaccination scheme for patients with MetS should be implemented due to the varying effectiveness rates observed in our study.

Insights into Omicron: Genomic Characterization and Inpatient Risk Assessment at Single Tertiary Hospital in Indonesia

Purpose

Omicron is a variant with the highest number of mutations among all Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) viruses, making whole genome sequencing (WGS) an essential tool for public health surveillance and molecular epidemiology. It is important to note that surveillance data can provide insights into the virus evolution and disease control. This study aims to provide an overview of WGS results for the SARS-CoV-2 Omicron Variant at Hasan Sadikin General Hospital Bandung.

Patients and Methods

This study was conducted using an analytical observational method. Data was collected retrospectively from medical records, SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) results, and WGS results of patients at Hasan Sadikin General Hospital Bandung from July to December 2022, who met the inclusion criteria. The lineage trends, mutation profiles, characteristics differences, and factors influencing hospitalization were also described.

Results

Among 239 subjects, 50 Omicron lineages were identified, with BA.5.2 (28%) and XBB.1 (19.2%) dominating since July and October 2022, respectively. The spike gene had the highest frequency, accounting for 28.8% out of the 532 types of mutations identified. In BA.5.2 lineage, 97.01, 92.53, and 100% had L452R mutation, F486V mutation, and H69/V70 deletion, respectively. In the XBB.1 lineage, 100% had R346T and N460K mutations, with no H69/V70 deletion observed. XBB.1 lineage was associated with a 5.49 times greater risk of inpatient treatment (95% CI: 1.73-17.38) compared to BA.5.2, while the adjusted odds ratio (aOR) for the number of vaccinations was 0.45 (95% CI: 0.29-0.7).

Conclusion

BA.5.2 and XBB.1 lineage dominated Omicron variant infections from July to December 2022, with the most mutations occurring in the spike gene. Inpatient risk was influenced by the type of lineage, with XBB.1 showing a higher risk. A greater number of vaccinations significantly reduced this risk, emphasizing the protective role of vaccination.

Impact of Vaccination Status on COVID-19 Severity and Pulmonary Involvement

Background and Objectives: The COVID-19 pandemic has had a significant impact on global health, with serious outcomes, such as lung damage, being major determinants of patient morbidity and mortality. Immunization has been essential in attenuating these outcomes. This study aimed to evaluate the impact of COVID-19 vaccination on disease severity, particularly focusing on pulmonary involvement, among hospitalized patients. Materials and Methods: A retrospective cohort study was conducted at Victor Babes Hospital, Timisoara, involving 3005 patients diagnosed with COVID-19 between December 2020 and March 2022. Patients were stratified into vaccinated and unvaccinated groups. Results: The study found that vaccinated patients had significantly lower rates of severe pulmonary involvement compared to unvaccinated patients. Specifically, only 24.24% of vaccinated patients experienced severe lung involvement, compared to 35.64% in the unvaccinated group (p < 0.001). Vaccinated individuals had shorter hospital stays (8.96 ± 6.40 days vs. 10.70 ± 6.29 days), but this difference was not statistically significant (p = 0.219). Additionally, chronic pulmonary diseases and stroke were less prevalent among vaccinated patients, highlighting the protective effect of vaccination. Conclusions: COVID-19 vaccination significantly reduces the severity of disease, particularly in preventing severe pulmonary involvement, which is a major determinant of patient outcomes. These findings underscore the importance of ongoing vaccination efforts and the need for booster doses to maintain immunity, especially as new variants emerge. The study supports the continued prioritization of vaccination in public health strategies to mitigate the long-term impact of COVID-19.

BBIBP-CorV vaccine effectiveness against COVID-19 in patients aged 60 years and older during the Delta-dominant period in the Federation of Bosnia and Herzegovina, a test-negative case-control study

COVID-19 vaccine uptake in the Federation of Bosnia and Herzegovina (FBiH) accelerated in the second half of 2021, with greater vaccine availability. In this study, we estimated the vaccine effectiveness (VE) of complete primary series BBIBP-CorV vaccine against COVID-19 in patients aged 60 years and older, during the Delta-dominant period, using a test-negative case-control design. Surveillance sites were 11 primary health care centers (PHC) collecting patient data from October 1, 2021, to January 4, 2022, retrospectively according to a common protocol. In total, we included 1711 participants in the analysis: 933 cases and 778 controls. Of the 933 cases, 508 (54.4 %) had mild and 425 (45.6 %) had moderate to severe disease presentation. We observed no effectiveness against mild COVID-19. Overall vaccine effectiveness was 65.0 % (95 %CI: 40.1-79.5) against moderate to severe COVID-19. In time since vaccination analysis, VE was 78.7 % (95 % CI: 54.8-89.9) in patients who received their last dose < 90 days before onset; 66.0 % (95 % CI: -0.5-88.5) in those 90-119 days before onset; 42.1 % (95 % CI: -88.6-82.3) in those 120-149 days before onset and 45.0 % (95 % CI: -94.0-84.4) in those ≥ 150 days before onset. In our study, two doses of BBIBP-CorV provided considerable protection against moderate to severe COVID-19 in older adults, highest within 3 months after second dose, during the Delta-dominant period. Point estimates declined thereafter, suggesting a need for additional doses.

Unveiling Inter- and Intra-Patient Sequence Variability with a Multi-Sample Coronavirus Target Enrichment Approach

Amid the global challenges posed by the COVID-19 pandemic, unraveling the genomic intricacies of SARS-CoV-2 became crucial. This study explores viral evolution using an innovative high-throughput next-generation sequencing (NGS) approach. By taking advantage of nasal swab and mouthwash samples from patients who tested positive for COVID-19 across different geographical regions during sequential infection waves, our study applied a targeted enrichment protocol and pooling strategy to increase detection sensitivity. The approach was extremely efficient, yielding a large number of reads and mutations distributed across 10 distinct viral gene regions. Notably, the genes Envelope, Nucleocapsid, and Open Reading Frame 8 had the highest number of unique mutations per 1000 nucleotides, with both spike and Nucleocapsid genes showing evidence for positive selection. Focusing on the spike protein gene, crucial in virus replication and immunogenicity, our findings show a dynamic SARS-CoV-2 evolution, emphasizing the virus-host interplay. Moreover, the pooling strategy facilitated subtle sequence variability detection. Our findings painted a dynamic portrait of SARS-CoV-2 evolution, emphasizing the intricate interplay between the virus and its host populations and accentuating the importance of continuous genomic surveillance to understand viral dynamics. As SARS-CoV-2 continues to evolve, this approach proves to be a powerful, versatile, fast, and cost-efficient screening tool for unraveling emerging variants, fostering understanding of the virus's genetic landscape.

Non-specific protection against severe COVID-19 associated to typhoid fever and DTP vaccination

Trained immunity (TRAIM) or the enhanced non-specific immune response after primary stimulation by infection or vaccination is a recent but well-recognized concept. To verify its predictions, our objective was to determine the effects of two bacterial vaccines, typhoid fever (TFV) and diphtheria-tetanus-pertussis (DTP) on the infection, hospitalization and death frequencies associated to COVID-19 in a retrospective study on subjects vaccinated or not with TFV and DTP in the 4 years prior to the start of COVID-19 pandemia in the Basque Country (Spain). The studied outcome records were split into two periods according to COVID-19 vaccination, the pre-vaccination (ACV) from March to December 2020 and the post-vaccination (PCV) from September 2021 to June 2022). In total, 13,673 subjects were vaccinated against TFV and 42,997 against DTP. A total of 2,005,084 individual records were studied in the ACV period and 1,436,693 in the PCV period. The proportion of infection, hospitalization and death associated to COVID-19 among controls in ACV was 4.97 %, 7.14 % and 3.54 %, respectively vs. 7.20 %, 2.24 % and 0.10 % among TFV subjects. Regarding DTP, the proportions were 4.97 %, 7.12 % and 3.58 % for controls and 5.79 %, 5.79 % and 0.80 % for vaccinees. In the PCV period, the proportion of infection, hospitalization and death among controls was 21.89 %, 2.62 % and 0.92 %, respectively vs. 31.19 %, 0.76 %, 0.00 % among TFV. For DTP, infection, hospitalization and death proportions were 21.89 %, 2.62 % and 0.92 %, respectively, among controls vs. 32.03 %, 1.85 % and 0.24 % among vaccinated subjects. The corresponding combined ACV and PCV odds ratios (OR) for SARS-CoV2 infection were 1.505 (95%CI 1.455-1.558; p < 0.0001; reduction -41.85 %) and 1.633 (95%CI 1.603-1.662; p < 0.0001; reduction -51.74 %), for TFV and DTP, respectively. Regarding COVID-19 associated hospitalization, the OR were 0.295 (95%CI 0.220-0.396; p = 0.0001; reduction 69.74 %) and 0.667 (95%CI 0.601-0.741; p = 0.0001; reduction 32.44 %), for TFV and DTP, respectively). COVID-19 associated death OR were 0.016 (95%CI 0.002-0.113, p < 0.0001; reduction 98.38 %) and 0.212 (95%CI 0.161-0.280; p = 0.0001; reduction 78.52 %), for TFV and DTP, respectively. We conclude that TRAIM effects by TFV and DTP vaccination in the four years prior to the pandemic SARS-CoV2 were supported by slightly increased infection rates, but strongly reduced COVID-19 associated hospitalization and death rates.

Vaccine Effectiveness against SARS-CoV-2 Infection during the Circulation of Alpha, Delta, or Omicron Variants: A Retrospective Cohort Study in a Tertiary Hospital in Serbia

The COVID-19 pandemic prompted rapid vaccine development and deployment worldwide. Despite widespread vaccination efforts, understanding the effectiveness of vaccines in hospitalized patients remains a critical concern. This retrospective cohort study, conducted at a tertiary healthcare centre in Serbia, tracked patients hospitalized during different waves of COVID-19 variants-Alpha, Delta, and Omicron. Data collection included demographics, comorbidities, symptoms, and vaccination status. Among 3593 patients, those with prior exposure to COVID-19 cases or hospital treatment showed higher positivity rates. Symptom prevalence varied across waves, with coughs persisting. Patients without chronic diseases were more frequent among those testing negative. Vaccine effectiveness varied, with Sinopharm demonstrating a 45.6% effectiveness initially and Pfizer-BioNTech showing an effectiveness of up to 74.8% within 0-84 days after the second dose. Mixed-dose strategies, notably Sinopharm as a primary dose followed by a Pfizer-BioNTech booster, suggested increased protection. Despite substantial vaccination availability, a significant portion of hospitalized patients remained unvaccinated. This study underscores the dynamic nature of vaccine effectiveness and advocates for booster strategies to address evolving challenges in combating COVID-19, particularly in hospitalized patients.

Clinical characteristics, outcomes, and risk factors of SARS-CoV-2 breakthrough infections among 572 fully vaccinated (BBIBP-CorV) hospitalized patients

Background

Breakthrough infections have been widely reported in vaccinated individuals. However, the clinical characteristics, outcomes, and risk factors of SARS-CoV-2 breakthrough infections among fully vaccinated (BBIBP-CorV) hospitalized patients have not yet been fully elucidated.

Methods

In the single-center cohort study conducted at Xiangya Hospital of Central South University, we enrolled the hospitalized COVID-19 patients who had received full (2 doses) vaccination with the BBIBP-CorV vaccine between December 5, 2022, and January 31, 2023. We collected and analyzed information related to clinical characteristics, laboratory results, treatments, outcomes and prognostic data. Univariate and multivariable Cox regression were performed to assess the impact of clinical characteristics and laboratory results on the composite outcome (including the initiation of endotracheal intubation, non-invasive respiratory support, intensive care unit admission, and all-cause death).

Results

A total of 572 COVID-19 hospitalized patients with fully vaccinated (BBIBP-CorV) were included. The median age of the patients was 66 years (IQR 53, 74). The most common symptoms included fever (347 [60.7 %]), dry cough (401 [70.1 %]), and expectoration (333 [58.2 %]). Among those with pre-existing chronic comorbidities, 44.2 % had hypertension and 20.5 % had diabetes. Laboratory tests revealed that the majority of patients (425/549 [77.4 %]) had normal white blood cell counts. Composite outcome occurred in 11.9 % of patients, with 96.7 % of patients discharged and 3.3 % of patients died. Multivariate Cox regression analyses suggested that the NLR >4 (adjusted HR, 5.50 [95%CI: 1.56-19.47]; P = 0.008), D-dimer >0.5 mg/ml (adjusted HR, 2.17 [95%CI: 1.03-4.59]; P = 0.042) and procalcitonin >0.1 ng/ml (adjusted HR, 3.22 [95%CI: 1.38-7.52]; P = 0.007) were independently associated with the composite outcome.

Conclusion

Breakthrough infection after being fully vaccinated (BBIBP-CorV) is more likely to occur in older patients and patients with pre-existing chronic comorbidities. NLR >4, D-dimer >0.5 mg/ml and procalcitonin >0.1 ng/ml were independent risk factors for composite outcome.