Development and validation of a multi-dimensional COVID-19 vaccine hesitancy questionnaire.

Background: Since the emergence of the COVID-19 pandemic, vaccines have been developed to tackle the disease. However, many people worldwide were not confident enough to take the vaccines. Developing a questionnaire to measure COVID-19 vaccine hesitancy will give the health authorities and policymakers a clear picture to establish appropriate interventions addressing vaccine hesitancy among the community. Methods: In this study, we used a mixed-method design over two phases. Phase 1 entailed a qualitative approach to developing the questionnaire, including a literature search, expert panel review, and focus group discussion. Phase 2 used a quantitative method for establishing the content and construct validity of the questionnaire via exploratory and confirmatory factor analysis (EFA & CFA). Internal consistency was checked using Cronbach's Alpha and intraclass correlation coefficient. Results: We developed a 50-item instrument designed to measure COVID-19 vaccine hesitancy among adults in the state of Qatar. The study involved 545 adult participants. In terms of content validity, our study showed a value of 0.92 for the scale-level content validity index based on the average and a value of 0.76 for the scale-level content validity index - universal agreement. In the EFA, the Kaiser-Meyer-Olkin measure of sampling adequacy was calculated at 0.78, with statistical significance (P = 0.001). Regarding model fit indices of the seven-factor model, our findings showed an acceptable model-data-fit, with a relative chi-square: 1.7 (<3), Root mean square error of approximation: 0.05 (<0.08), PCLOSE = 0.41, Comparative fit index: 0.909, Tucker-Lewis index: 0.902, Incremental Fit Index: 0.910 and, Standardized Root mean square residual: 0.067 (<0.08). The seven-factor model of the questionnaire met the criterion of good internal consistency (Cronbach's alpha = 0.73). Conclusion: This tool is deemed of methodological merits in terms of validity, reliability, and determining the underlying conceptual structure of COVID-19 vaccine hesitancy and its associating factors.

Association between Multimorbidity and COVID-19 Mortality in Qatar: A Cross-Sectional Study

This study assessed the association between multimorbidity and mortality from COVID-19 in the Middle East and North Africa region, where such data are scarce. We conducted a cross-sectional study using data of all cases with COVID-19 reported to the Ministry of Public Health of Qatar from March to September 2020. Data on pre-existing comorbidities were collected using a questionnaire and multimorbidity was defined as having at least two comorbidities. Proportions of deaths were compared by comorbidity and multimorbidity status and multivariable logistic regression analyses were carried out. A total of 92,426 participants with a mean age of 37.0 years (SD 11.0) were included. Mortality due to COVID-19 was associated with gastrointestinal diseases (aOR 3.1, 95% CI 1.16-8.30), respiratory diseases (aOR 2.9, 95% CI 1.57-5.26), neurological diseases (aOR 2.6, 95% CI 1.19-5.54), diabetes (aOR 1.8, 95% CI 1.24-2.61), and CVD (aOR 1.5, 95% CI 1.03-2.22). COVID-19 mortality was strongly associated with increasing multimorbidity;one comorbidity (aOR 2.0, 95% CI 1.28-3.12), two comorbidities (aOR 2.8, 95% CI 1.79-4.38), three comorbidities (aOR 6.0, 95% 3.34-10.86) and four or more comorbidities (aOR 4.15, 95% 1.3-12.88). This study demonstrates a strong association between COVID-19 mortality and multimorbidity in Qatar.

Duration of COVID-19 mRNA Vaccine Effectiveness against Severe Disease.

Waning immunity following administration of mRNA-based COVID-19 vaccines remains a concern for many health systems. We undertook a study to determine if recent reports of waning for severe disease could have been attributed to design-related bias by conducting a study only among those detected with a first SARS-CoV-2 infection. We used a matched case-control study design with the study base being all individuals with first infection with SARS-CoV-2 reported in the State of Qatar between 1 January 2021 and 20 February 2022. Cases were those detected with first SARS-CoV-2 infection requiring intensive care (hard outcome), while controls were those detected with first SARS-CoV-2 infection who recovered without the need for intensive care. Cases and controls were matched in a 1:30 ratio for the calendar month of infection and the comorbidity category. Duration and magnitude of conditional vaccine effectiveness against requiring intensive care and the number needed to vaccinate (NNV) to prevent one more case of COVID-19 requiring intensive care was estimated for the mRNA (BNT162b2/mRNA-1273) vaccines. Conditional vaccine effectiveness against requiring intensive care was 59% (95% confidence interval (CI), 50 to 76) between the first and second dose, and strengthened to 89% (95% CI, 85 to 92) between the second dose and 4 months post the second dose in persons who received a primary course of the vaccine. There was no waning of vaccine effectiveness in the period from 4 to 6, 6 to 9, and 9 to 12 months after the second dose. This study demonstrates that, contrary to mainstream reports using hierarchical measures of effectiveness, conditional vaccine effectiveness against requiring intensive care remains robust till at least 12 months after the second dose of mRNA-based vaccines.

Prevalence and determinants of symptomatic COVID-19 infection among children and adolescents in Qatar: a cross-sectional analysis of 11 445 individuals.

There is a paucity of evidence about the prevalence and risk factors for symptomatic infection among children. This study aimed to describe the prevalence of symptomatic coronavirus disease 2019 (COVID-19) and its risk factors in children and adolescents aged 0-18 years in Qatar. We conducted a cross-sectional study of all children aged 0-18 years diagnosed with COVID-19 using polymerase chain reaction in Qatar during the period 1st March to 31st July 2020. A generalised linear model with a binomial family and identity link was used to assess the association between selected factors and the prevalence of symptomatic infection. A total of 11 445 children with a median age of 8 years (interquartile range (IQR) 3-13 years) were included in this study. The prevalence of symptomatic COVID-19 was 36.6% (95% confidence interval (CI) 35.7-37.5), and it was similar between children aged <5 years (37.8%), 5-9 years (34.3%) and 10 + years (37.3%). The most frequently reported symptoms among the symptomatic group were fever (73.5%), cough (34.8%), headache (23.2%) and sore throat (23.2%). Fever (82.8%) was more common in symptomatic children aged <5 years, while cough (38.7%) was more prevalent in those aged 10 years or older, compared to other age groups. Variables associated with an increased risk of symptomatic infection were; contact with confirmed cases (RD 0.21; 95% CI 0.20-0.23; P = 0.001), having visited a health care facility (RD 0.54; 95% CI 0.45-0.62; P = 0.001), and children aged under 5 years (RD 0.05; 95% CI 0.02-0.07; P = 0.001) or aged 10 years or older (RD 0.04; 95% CI 0.02-0.06; P = 0.001). A third of the children with COVID-19 were symptomatic with a higher proportion of fever in very young children and a higher proportion of cough in those between 10 and 18 years of age.