BNT162b2 Versus mRNA-1273 Vaccines: Comparative Analysis of Long-Term Protection Against SARS-CoV-2 Infection and Severe COVID-19 in Qatar.

Background: This study provides a head-to-head comparison of the protection provided by the BNT162b2 and mRNA-1273 vaccines against SARS-CoV-2 infection and against severe COVID-19, covering primary series and third dose/booster vaccinations over up to 3 years of follow-up, both before and after the emergence of the omicron variant.

Methods: Two national, matched, retrospective cohort studies were conducted on Qatar's vaccinated population from December 16, 2020, to February 18, 2024. Subgroup analyses by pre-vaccination SARS-CoV-2 infection history, as well as sensitivity analyses, were also conducted.

Effectiveness of two and three doses of COVID-19 mRNA vaccines against infection, symptoms, and severity in the pre-omicron era: A time-dependent gradient.

Background: Vaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and mRNA-1273 mRNA vaccines against a spectrum of SARS-CoV-2 infection symptoms and severities.

Methods: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests.

Protection of natural infection against reinfection with SARS-CoV-2 JN.1 variant.

Overall effectiveness of infection in preventing reinfection with SARS-CoV-2 JN.1 variant was estimated at 1.8% (95% CI: −9.

Addressing bias in the definition of SARS-CoV-2 reinfection: implications for underestimation.

Introduction: Reinfections are increasingly becoming a feature in the epidemiology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, accurately defining reinfection poses methodological challenges. Conventionally, reinfection is defined as a positive test occurring at least 90 days after a previous infection diagnosis.

Direct vertebral rotation versus simple rod derotation techniques in correction of adolescent idiopathic scoliosis.

Background: One method for treating adolescent idiopathic scoliosis (AIS), which is characterized by abnormal spinal alignment in the coronal, sagittal, and rotational planes, is surgical correction. The two surgical techniques most typically used to correct spine alignment are simple rod derotation (SRD) and direct vertebral derotation (DVR).

Aim: The study's goal was to assess the effectiveness of two treatment methods for adolescent idiopathic scoliosis: simple rod derotation and direct vertebral rotation.

SARS-CoV-2 infection and effects of age, sex, comorbidity, and vaccination among older individuals: A national cohort study.

Background: We investigated the contribution of age, coexisting medical conditions, sex, and vaccination to incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and of severe, critical, or fatal COVID-19 in older adults since pandemic onset.

Methods: A national retrospective cohort study was conducted in the population of Qatar aged ≥50 years between February 5, 2020 and June 15, 2023. Adjusted hazard ratios (AHRs) for infection and for severe coronavirus disease 2019 (COVID-19) outcomes were estimated through Cox regression models.

History of primary-series and booster vaccination and protection against Omicron reinfection.

Laboratory evidence suggests a possibility of immune imprinting for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We investigated the differences in the incidence of SARS-CoV-2 reinfection in a cohort of persons who had a primary Omicron infection, but different vaccination histories using matched, national, retrospective, cohort studies. Adjusted hazard ratio for reinfection incidence, factoring adjustment for differences in testing rate, was 0.

Short- and longer-term all-cause mortality among SARS-CoV-2- infected individuals and the pull-forward phenomenon in Qatar: a national cohort study.

Objectives: We assessed short-, medium-, and long-term all-cause mortality risks after a primary SARS-CoV-2 infection.

Methods: A national, matched, retrospective cohort study was conducted in Qatar to assess risk of all-cause mortality in the national SARS-CoV-2 primary infection cohort compared with the national infection-naïve cohort. Associations were estimated using Cox proportional-hazards regression models.

Bivalent mRNA-1273.214 vaccine effectiveness against SARS-CoV-2 omicron XBB* infections.

Effectiveness of the 50-μg mRNA-1273.214 bivalent vaccine against SARS-CoV-2 infection was modest at 25% in a matched, retrospective, cohort study in Qatar comparing infection incidence in the bivalent cohort to that in the national no-recent-vaccination resident cohort. XBB* immune evasion, immune imprinting effects, or both, may explain findings.

Effects of previous infection, vaccination, and hybrid immunity against symptomatic Alpha, Beta, and Delta SARS-CoV-2 infections: an observational study.

Background: Protection against SARS-CoV-2 symptomatic infection and severe COVID-19 of previous infection, mRNA two-dose vaccination, mRNA three-dose vaccination, and hybrid immunity of previous infection and vaccination were investigated in Qatar for the Alpha, Beta, and Delta variants.

Methods: Six national, matched, test-negative, case-control studies were conducted between January 18 and December 18, 2021 on a sample of 239,120 PCR-positive tests and 6,103,365 PCR-negative tests.

Findings: Effectiveness of previous infection against Alpha, Beta, and Delta reinfection was 89.

All-cause and COVID-19 mortality in Qatar during the COVID-19 pandemic.

Objective: To investigate all-cause mortality, COVID-19 mortality and all-cause non-COVID-19 mortality in Qatar during the COVID-19 pandemic.

Methods: A national, retrospective cohort analysis and national, matched, retrospective cohort studies were conducted between 5 February 2020 and 19 September 2022.

Results: There were 5025 deaths during a follow-up time of 5 247 220 person-years, of which 675 were COVID-19 related.

Immediate and contributory causes of death in patients hospitalized with COVID-19.

Objectives: Accurate determination of the immediate causes of death in patients with COVID-19 is important for optimal care and mitigation strategies.

Methods: All deaths in Qatar between March 01, 2020, and August 31, 2022, flagged for likely relationship to COVID-19 were reviewed by two independent, trained reviewers using a standardized methodology to determine the immediate and contributory causes of death.

Results: Among 749 flagged deaths, the most common admitting diagnoses were respiratory tract infection (91%) and major adverse cardiac event (MACE, 2.

Long-term COVID-19 booster effectiveness by infection history and clinical vulnerability and immune imprinting: a retrospective population-based cohort study.

Background: Long-term effectiveness of COVID-19 mRNA boosters in populations with different previous infection histories and clinical vulnerability profiles is inadequately understood. We aimed to investigate the effectiveness of a booster (third dose) vaccination against SARS-CoV-2 infection and against severe, critical, or fatal COVID-19, relative to that of primary-series (two-dose) vaccination over a follow-up duration of 1 year.

Methods: This observational, matched, retrospective, cohort study was done on the population of Qatar in people with different immune histories and different clinical vulnerability to infection.

Effectiveness of influenza vaccination against SARS-CoV-2 infection among healthcare workers in Qatar.

Background: Some studies have reported that influenza vaccination is associated with lower risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and/or coronavirus disease 2019 (COVID-19) morbidity and mortality. This study aims to estimate effectiveness of influenza vaccination, using Abbott's quadrivalent Influvac Tetra vaccine, against SARS-CoV-2 infection and against severe COVID-19.

Methods: This matched, test-negative, case-control study was implemented on a population of 30,774 healthcare workers (HCWs) in Qatar during the 2020 annual influenza vaccination campaign, September 17, 2020-December 31, 2020, before introduction of COVID-19 vaccination.

Protection from previous natural infection compared with mRNA vaccination against SARS-CoV-2 infection and severe COVID-19 in Qatar: a retrospective cohort study.

Background: Understanding protection conferred by natural SARS-CoV-2 infection versus COVID-19 vaccination is important for informing vaccine mandate decisions. We compared protection conferred by natural infection versus that from the BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines in Qatar.

Methods: We conducted two matched retrospective cohort studies that emulated target trials.

Caps Captioning: A Modern Image Captioning Approach Based on Improved Capsule Network.

In image captioning models, the main challenge in describing an image is identifying all the objects by precisely considering the relationships between the objects and producing various captions. Over the past few years, many methods have been proposed, from an attribute-to-attribute comparison approach to handling issues related to semantics and their relationships. Despite the improvements, the existing techniques suffer from inadequate positional and geometrical attributes concepts.

Covid-19 Vaccine Protection among Children and Adolescents in Qatar.

Background: The BNT162b2 vaccine against coronavirus disease 2019 (Covid-19) has been authorized for use in children 5 to 11 years of age and adolescents 12 to 17 years of age but in different antigen doses.

Methods: We assessed the real-world effectiveness of the BNT162b2 vaccine against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and adolescents in Qatar. To compare the incidence of SARS-CoV-2 infection in the national cohort of vaccinated participants with the incidence in the national cohort of unvaccinated participants, we conducted three matched, retrospective, target-trial, cohort studies - one assessing data obtained from children 5 to 11 years of age after the B.

Effectiveness of the neutralizing antibody sotrovimab among high-risk patients with mild-to-moderate SARS-CoV-2 in Qatar.

Objectives: To estimate the real-world effectiveness of sotrovimab against severe, critical, or fatal COVID-19 in Qatar at a time in which most SARS-CoV-2 incidences occurred due to the BA.2 Omicron subvariant.

Methods: We conducted a matched case-control study among all individuals eligible for sotrovimab treatment per United States Food and Drug Administration guidelines in the resident population of Qatar.

Duration of immune protection of SARS-CoV-2 natural infection against reinfection.

Background: The future of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic hinges on virus evolution and duration of immune protection of natural infection against reinfection. We investigated the duration of protection afforded by natural infection, the effect of viral immune evasion on duration of protection and protection against severe reinfection, in Qatar, between 28 February 2020 and 5 June 2022.

Methods: Three national, matched, retrospective cohort studies were conducted to compare the incidence of SARS-CoV-2 infection and coronavirus disease 2019 (COVID-19) severity among unvaccinated persons with a documented SARS-CoV-2 primary infection, to incidence among those infection-naïve and unvaccinated.