An intersectional analysis of sociodemographic disparities in Covid-19 vaccination: A nationwide register-based study in Sweden

Area and individual level analyses of demographic and socio-economic disparities in COVID-19 vaccination uptake in Belgium

Vaccination has played a major role in overcoming the COVID-19 pandemic. However, vaccination status can be influenced by demographic and socio-economic factors at individual and area level. In the context of the LINK-VACC project, the Belgian vaccine register for the COVID-19 vaccination campaign was linked at individual level with other registers, notably the COVID-19 laboratory test results and demographic and socio-economic variables from the DEMOBEL database. The present article aims at investigating to which extent COVID-19 vaccination status is associated with area level and/or individual level demographic and socio-economic factors. From a sample of all individuals tested for SARS-CoV-2 (LINK-VACC sample) demographic and socio-economic indicators are derived and their impact on vaccination coverages at an aggregated geographical level (municipality) is quantified. The same indicators are calculated for the full Belgian population, allowing to assess the representativeness of the LINK-VACC sample with respect to the impact of demographic and socio-economic disparities on vaccination uptake. In a second step, hierarchical models are fitted to the individual level LINK-VACC data to disentangle the individual and municipality effects allowing to evaluate the added value of the availability of individual level data in this context. The most important effects observed at the individual level are reflected in the aggregated data at the municipality level. Multilevel analyses show that most of the demographic and socio-economic impacts on vaccination are captured at the individual level, although accounting for area level in individual level analyses improve the overall description.

Are the 7C psychological antecedents associated with COVID-19 vaccine behaviours beyond intentions? A cross-sectional study on at-least-one-dose and up-to-date vaccination status, and uptake speed among adults in France

BACKGROUND

Widely documented psychological antecedents of vaccination are confidence in vaccines, complacency, convenience, calculation, collective responsibility (5C model) with the recent addition of confidence in the wider system and social conformism. While the capacity of these seven antecedents (7C) to explain variance in COVID-19 vaccine intentions has been previously documented, we study whether these factors also are associated with vaccine behaviours, beyond intentions.

METHODS

From February to June 2022, we recruited a sample of adults in France, including persons with notified recent SARS-CoV-2 infection, along with relatives and randomly selected non-infected persons. Participants completed self-administered questionnaires assessing COVID-19 vaccination history and the 7C antecedents. We defined vaccination behaviours as three outcomes: at-least-one-dose vaccine status by 2022 (N = 49,019), up-to-date vaccination status (N = 46,566), and uptake speed of first dose (N = 25,998). We conducted multivariable logistic regressions and Cox models.

RESULTS

Among the 49,019 participants, 95.0% reported receipt of at least one dose and 89.8% were up to date with recommendations. All 7C antecedents were significantly associated with the outcomes, although effects were weaker for up-to-date vaccination status and uptake speed. The strongest effects (most vs. least vaccine-favourable attitude level, at-least-one-dose vaccination status) were observed for collective responsibility (OR: 14.44; 95%CI: 10.72-19.45), calculation (OR: 10.29; 95%CI: 7.53-14.05), and confidence in the wider system (OR: 8.94; 95%CI: 6.51-12.27).

CONCLUSION

This study demonstrates that the 7C not only explain vaccine intention, but also vaccine behaviours, and underpins the importance of developing vaccine promotion strategies considering the 7C antecedents.

Understanding the factors associated with COVID-19 vaccine hesitancy in Venezuela

BACKGROUND

Despite nearly a quarter of Venezuelans remaining unvaccinated against coronavirus disease 2019 (COVID-19), the factors contributing to vaccine hesitancy in the country have not been thoroughly investigated.

METHODS

A cross-sectional study was conducted from October 15th to 30th, 2022, using a knowledge, attitudes, and practices (KAP) survey to identify factors associated with COVID-19 vaccine hesitancy.

RESULTS

The study analyzed data from 1,930 participants from all 24 states of Venezuela. The majority (93.4%) were vaccinated. The mean age was 40 years, predominantly female (67.3%), and held a university degree (70.6%). The mean KAP score was significantly higher among vaccinated individuals compared to unvaccinated ones (7.79 vs. 3.94 points for knowledge, 40 vs. 24 points for attitudes, and 16 vs. 10 points for practices, all p < 0.001). Increases in the scores for KAP were associated with increased odds of being vaccinated (84.6%, 25.6%, and 33% respectively for each one-point increase, all p < 0.001). Certain demographic factors such as marital status, occupation, religious beliefs, monthly income, and location influence COVID-19 vaccine knowledge. Higher income and certain occupations decrease the odds of low knowledge, while residing in specific states increases it. Attitudes towards the COVID-19 vaccine are influenced by age, health status, vaccination status, and location. Higher income and absence of certain health conditions decrease the odds of negative attitudes. Lastly, age, occupation, monthly income, and location affect vaccine practices. Advanced age and higher income decrease the odds of inappropriate practices, while residing in La Guaira state increases them.

CONCLUSION

Factors such as age, education level, occupation, monthly income, and location were found to be associated with knowledge and attitudes towards COVID-19 vaccine among the surveyed Venezuelans.

The sociodemographic patterning of sick leave and determinants of longer sick leave after mild and severe COVID-19: a nationwide register-based study in Sweden

BACKGROUND

Studies on sociodemographic differences in sick leave after coronavirus disease 2019 (COVID-19) are limited and research on COVID-19 long-term health consequences has mainly addressed hospitalized individuals. The aim of this study was to investigate the social patterning of sick leave and determinants of longer sick leave after COVID-19 among mild and severe cases.

METHODS

The study population, from the Swedish multi-register observational study SCIFI-PEARL, included individuals aged 18-64 years in the Swedish population, gainfully employed, with a first positive polymerase chain reaction (PCR) test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from 1 January 2020 until 31 August 2021 (n = 661 780). Using logistic regression models, analyses were adjusted for sociodemographic factors, vaccination, prior sick leave, comorbidities and stratified by hospitalization.

RESULTS

In total, 37 420 (5.7%) individuals were on sick leave due to COVID-19 in connection with their first positive COVID-19 test. Individuals on sick leave were more often women, older, had lower income and/or were born outside Sweden. These differences were similar across COVID-19 pandemic phases. The highest proportion of sick leave was seen in the oldest age group (10.3%) with an odds ratio of 4.32 (95% confidence interval 4.18-4.47) compared with the youngest individuals. Among individuals hospitalized due to COVID-19, the sociodemographic pattern was less pronounced, and in some models, even reversed. The intersectional analysis revealed considerable variability in sick leave between sociodemographic groups (range: 1.5-17.0%).

CONCLUSION

In the entire Swedish population of gainfully employed individuals, our findings demonstrated evident sociodemographic differences in sick leave due to COVID-19. In the hospitalized group, the social patterning was different and less pronounced.

Machine learning-driven development of a disease risk score for COVID-19 hospitalization and mortality: a Swedish and Norwegian register-based study

Aims

To develop a disease risk score for COVID-19-related hospitalization and mortality in Sweden and externally validate it in Norway.

Method

We employed linked data from the national health registries of Sweden and Norway to conduct our study. We focused on individuals in Sweden with confirmed SARS-CoV-2 infection through RT-PCR testing up to August 2022 as our study cohort. Within this group, we identified hospitalized cases as those who were admitted to the hospital within 14 days of testing positive for SARS-CoV-2 and matched them with five controls from the same cohort who were not hospitalized due to SARS-CoV-2. Additionally, we identified individuals who died within 30 days after being hospitalized for COVID-19. To develop our disease risk scores, we considered various factors, including demographics, infectious, somatic, and mental health conditions, recorded diagnoses, and pharmacological treatments. We also conducted age-specific analyses and assessed model performance through 5-fold cross-validation. Finally, we performed external validation using data from the Norwegian population with COVID-19 up to December 2021.

Results

During the study period, a total of 124,560 individuals in Sweden were hospitalized, and 15,877 individuals died within 30 days following COVID-19 hospitalization. Disease risk scores for both hospitalization and mortality demonstrated predictive capabilities with ROC-AUC values of 0.70 and 0.72, respectively, across the entire study period. Notably, these scores exhibited a positive correlation with the likelihood of hospitalization or death. In the external validation using data from the Norwegian COVID-19 population (consisting of 53,744 individuals), the disease risk score predicted hospitalization with an AUC of 0.47 and death with an AUC of 0.74.

Conclusion

The disease risk score showed moderately good performance to predict COVID-19-related mortality but performed poorly in predicting hospitalization when externally validated.

Covid-19 vaccine effectiveness against post-covid-19 condition among 589 722 individuals in Sweden: population based cohort study

OBJECTIVE

To investigate the effectiveness of primary covid-19 vaccination (first two doses and first booster dose within the recommended schedule) against post-covid-19 condition (PCC).

DESIGN

Population based cohort study.

SETTING

Swedish Covid-19 Investigation for Future Insights-a Population Epidemiology Approach using Register Linkage (SCIFI-PEARL) project, a register based cohort study in Sweden.

PARTICIPANTS

All adults (≥18 years) with covid-19 first registered between 27 December 2020 and 9 February 2022 (n=589 722) in the two largest regions of Sweden. Individuals were followed from a first infection until death, emigration, vaccination, reinfection, a PCC diagnosis (ICD-10 diagnosis code U09.9), or end of follow-up (30 November 2022), whichever came first. Individuals who had received at least one dose of a covid-19 vaccine before infection were considered vaccinated.

MAIN OUTCOME MEASURE

The primary outcome was a clinical diagnosis of PCC. Vaccine effectiveness against PCC was estimated using Cox regressions adjusted for age, sex, comorbidities (diabetes and cardiovascular, respiratory, and psychiatric disease), number of healthcare contacts during 2019, socioeconomic factors, and dominant virus variant at time of infection.

RESULTS

Of 299 692 vaccinated individuals with covid-19, 1201 (0.4%) had a diagnosis of PCC during follow-up, compared with 4118 (1.4%) of 290 030 unvaccinated individuals. Covid-19 vaccination with any number of doses before infection was associated with a reduced risk of PCC (adjusted hazard ratio 0.42, 95% confidence interval 0.38 to 0.46), with a vaccine effectiveness of 58%. Of the vaccinated individuals, 21 111 received one dose only, 205 650 received two doses, and 72 931 received three or more doses. Vaccine effectiveness against PCC for one dose, two doses, and three or more doses was 21%, 59%, and 73%, respectively.

CONCLUSIONS

The results of this study suggest a strong association between covid-19 vaccination before infection and reduced risk of receiving a diagnosis of PCC. The findings highlight the importance of primary vaccination against covid-19 to reduce the population burden of PCC.

Social interactions and COVID-19 vaccine hesitancy: Evidence from a full population study in Sweden

We investigate whether an individual's information milieu-an individual's residential neighborhood and co-workers-affects the decision to get a COVID-19 vaccine. The decision to accept or refuse a vaccine is intensely personal and involves the processing of information about phenomena likely to be unfamiliar to most individuals. One can thus expect an interplay between an individual's level of education and skills and the information processing of others whom with whom she can interact and whose decision she can probe and observe. Using individual-level data for adults in Sweden, we can identify the proportion of an individual's neighborhood and workplace who are unvaccinated as indicators of possible peer effects. We find that individuals with low levels of educational attainment and occupational skills are more likely to be unvaccinated when exposed to other unvaccinated individuals at work and in the residential neighborhood. The peer effects in each of these information milieus further increases the likelihood of not getting vaccinated-with the two acting as information channels that reinforce one another.

Factors underlying COVID-19 booster vaccine uptake among adults in Belgium

OBJECTIVE

This study aimed to investigate factors influencing the uptake of first and second COVID-19 booster vaccines among adults in Belgium, particularly age, sex, region of residence and laboratory confirmed COVID-19 infection history.

RESULTS

A binomial regression model was used with having received the first or second booster as outcome and age, sex, region of residence and infection history as fixed variables. Among adults, there was generally a higher uptake to receive the first booster among older age groups compared to younger ones. Females, individuals residing in Flanders and those with no previous COVID-19 infection were more likely to receive the first booster. For the second booster, the same age trend was seen as for the first booster. Males, individuals residing in Flanders and those who tested positive for COVID-19 once after first booster were more likely to receive the second booster. Individuals with multiple positive COVID-19 tests before and after primary course or first booster were less likely to receive the subsequent booster dose compared to COVID-naïve individuals. This information could be used to guide future vaccination campaigns during a pandemic and can provide valuable insights into booster uptake patterns.

Sociodemographic disparities affect COVID-19 vaccine uptake in non-elderly adults with increased risk of severe COVID-19

BACKGROUND

There is limited information about sociodemographic disparities in COVID-19 vaccine uptake among non-elderly adults with an increased risk of severe COVID-19. We investigated the COVID-19 vaccine uptake in individuals aged 18-64 years with an increased risk of severe COVID-19 (non-elderly risk group) in Stockholm County, Sweden.

METHOD

We used population-based health and sociodemographic registries with high coverage to perform a cohort study of COVID-19 vaccine uptake of one to four doses up until 21 November 2022. The vaccine uptake in the non-elderly risk group was compared with non-risk groups aged 18-64 years (non-elderly non-risk group) and individuals aged ≥65 years (elderly).

RESULTS

The uptake of ≥3 vaccine doses was 55%, 64% and 87% in the non-elderly non-risk group (n = 1,005,182), non-elderly risk group (n = 308,904) and elderly (n = 422,604), respectively. Among non-elderly risk group conditions, Down syndrome showed the strongest positive association with receiving three doses (adjusted risk ratio [aRR] 1.62, 95% confidence interval [CI] 1.54-1.71), whereas chronic liver disease showed the strongest negative association (aRR 0.90, 95% CI 0.88-0.92). Higher vaccine uptake among the non-elderly risk group was associated with increasing age, being born in Sweden, higher education, higher income and living in a household where other adults had been vaccinated. Similar trends were observed for the first, second, third and fourth doses.

CONCLUSION

These results call for measures to tackle sociodemographic disparities in vaccination programmes during and beyond the COVID-19 pandemic.

Determinants of COVID-19 Vaccine Uptake in The Netherlands: A Nationwide Registry-Based Study

By September 2022, the uptake of at least one dose of COVID-19 vaccine in the Dutch adult population was 84%. Ecological studies have indicated a lower uptake in certain population groups. We aimed to investigate determinants of COVID-19 vaccine uptake in the Netherlands at individual level to evaluate and optimize implementation of the vaccination program and generate hypotheses for research on drivers of, and barriers to, vaccination. A retrospective database study was performed including the entire Dutch population ≥ 18. Vaccination data (5 January 2021-18 November 2021) were at individual levels linked to sociodemographic data. Random forest analyses ranked sociodemographic determinants of COVID-19 vaccine uptake. The most important determinant was age; uptake increased until the age of 80 (67% in 18-35 years, 92% in 67-79 years, and 88% in those > 80). Personal income and socioeconomic position ranked second and third, followed by migration status. Uptake was lower among individuals in the lowest income group (69%), those receiving social benefits (56%), and individuals with two parents born abroad (59%). Our finding that age is the most important determinant for uptake likely reflects the prioritisation of elderly in the programme and the general understanding of their increased vulnerability. However, our findings also reveal important other disparities in vaccine uptake. How to best address this inequity in future vaccination campaigns requires further research.

Inequalities in COVID-19 severe morbidity and mortality by country of birth in Sweden

Migrants have been more affected by the COVID-19 pandemic. Whether this has varied over the course of the pandemic remains unknown. We examined how inequalities in intensive care unit (ICU) admission and death related to COVID-19 by country of birth have evolved over the course of the pandemic, while considering the contribution of social conditions and vaccination uptake. A population-based cohort study was conducted including adults living in Sweden between March 1, 2020 and June 1, 2022 (n = 7,870,441). Poisson regressions found that migrants from Africa, Middle East, Asia and European countries without EU28/EEA, UK and Switzerland had higher risk of COVID-19 mortality and ICU admission than Swedish-born. High risks of COVID-19 ICU admission was also found in migrants from South America. Inequalities were generally reduced through subsequent waves of the pandemic. In many migrant groups socioeconomic status and living conditions contributed to the disparities while vaccination campaigns were decisive when such became available.

Geographic and Socioeconomic Determinants of Full Coverage COVID-19 Vaccination in Peru: Findings from a National Population-Based Study

Despite the fact that vaccination coverage against COVID-19 has made great progress in Peru, there is still a quarter of the population that has not been fully vaccinated. This study aims to determine the factors associated with complete vaccination in Peruvian adults. An analysis of the National Household Survey 2022 in Peru was performed. Prevalence ratios with their 95% confidence intervals (95% CI) were estimated to assess the factors associated with vaccination with three or more doses of the COVID-19 vaccine. A total of 58,471 participants were included in the study and 75.8% of the surveyed population were found to have received full vaccination. Significant differences in complete coverage were observed according to sex, age, educational level, ethnicity, poverty status, and geographic location. In the adjusted analysis, individuals aged 60 years or older, those with higher educational attainment, the non-poor, and those living in urban areas were more likely to be fully vaccinated. Native individuals and people who live in households without media are less likely to be fully covered. These results highlight the importance of considering demographic and socioeconomic factors when analyzing COVID-19 vaccination coverage. Additional strategies are needed to address vaccination gaps and ensure better vaccination coverage.

COVID-19 vaccination rates among adolescents (12-17 years) by immigrant background and sociodemographic factors: A nationwide registry study in Norway

PURPOSE

Lower COVID-19 vaccination rates have been observed among some adult immigrant populations in Norway, and there appears to be an association with sociodemographic factors. However, knowledge is lacking on the distribution of vaccination rates and role of sociodemographic factors among adolescents. This study aims to describe COVID-19 vaccination rates among adolescents according to immigrant background, household income, and parental education.

METHODS

In this nationwide registry study, we analyzed individual-level data on adolescents (12-17 years) from the Norwegian Emergency preparedness register for COVID-19 until September 15th, 2022. We estimated incidence rate ratios (IRR) for receiving at least one COVID-19 vaccine dose by country background, household income and parental education, using Poisson regression, adjusting for age, sex, and county.

RESULTS

The sample comprised 384,815 adolescents. Foreign-born and Norwegian-born with foreign-born parents, had lower vaccination rates (57 % and 58 %) compared to adolescents with at least one Norwegian-born parent (84 %). Vaccination rates by country background varied from 88 % (Vietnam) to 31 % (Russia). Variation and associations by country background, household income, and parental education were greater among 12-15-year-olds than 16-17-year-olds. Household income and parental education were positively associated with vaccination. Compared to the lowest income and education category, IRRs for household income ranged from 1.07 (95 % CI 1.06-1.09) to 1.31 (95 % CI 1.29-1.33) among 12-15-year-olds, and 1.06 (95 % CI 1.04-1.07) to 1.17 (95 % CI 1.15-1.18) among 16-17-year-olds. For parental education, from IRR 1.08 (95 % CI 1.06-1.09) to 1.18 (95 % CI 1.17-1.20) among 12-15-year-olds, and 1.05 (95 % CI 1.04-1.07) to 1.09 (95 % CI 1.07-1.10) among 16-17-year-olds.

CONCLUSION

COVID-19 vaccination rates varied by immigrant background and age group, with lower rates especially among adolescents with background from Eastern Europe and among younger adolescents. Household income and parental education were positively associated with vaccination rates. Our results may help target measures to increase vaccination rates among adolescents.

The COVID-19 Israeli tapestry: the intersectionality health equity challenge

BACKGROUND

COVID-19 is disproportionately affecting disadvantaged populations, with greater representation and worse outcomes in low socioeconomic and minority populations, and in persons from marginalized groups. General health care system approaches to inequity reduction (i.e., the minimization of differences in health and health care which are considered unfair or unjust), address the major social determinants of health, such as low income, ethnic affiliation or remote place of residents. Yet, to effectively reduce inequity there is a need for a multifactorial consideration of the aspects that intersect and generate significant barriers to effective care that can address the unique situations that people face due to their gender, ethnicity and socioeconomic situation.

MAIN BODY

To address the health equity challenges of diverse population groups in Israel, we propose to adopt an intersectional approach, allowing to better identify the needs and then better tailor the infection prevention and control modalities to those who need them the most. We focus on the two main ethnic - cultural-religious minority groups, that of Arab Palestinian citizens of Israel and Jewish ultra-orthodox (Haredi) communities. Additionally, we address the unique needs of persons with severe mental illness who often experience an intersection of clinical and sociodemographic risks.

CONCLUSIONS

This perspective highlights the need for responses to COVID-19, and future pandemic or global disasters, that adopt the unique lens of intersectionality and equity. This requires that the government and health system create multiple messages, interventions and policies which ensure a person and community tailored approach to meet the needs of persons from diverse linguistic, ethnic, religious, socioeconomic and cultural backgrounds. Under-investment in intersectional responses will lead to widening of gaps and a disproportionate disease and mortality burden on societies' most vulnerable groups.

Coverage of primary and booster vaccination against COVID-19 by socioeconomic level: A nationwide cross-sectional registry study

High and equitable COVID-19 vaccination coverage is important for pandemic control and prevention of health inequity. However, little is known about socioeconomic correlates of booster vaccination coverage. In this cross-sectional study of all Norwegian adults in the national vaccination program (N = 4,190,655), we use individual-level registry data to examine coverage by levels of household income and education of primary (≥2 doses) and booster (≥3 doses) vaccination against COVID-19. We stratify the analyses by age groups with different booster recommendations and report relative risk ratios (RR) for vaccination by 25 August 2022. In the 18-44 y group, individuals with highest vs. lowest education had 94% vs. 79% primary coverage (adjusted RR (adjRR) 1.15, 95%CI 1.14-1.15) and 67% vs. 38% booster coverage (adjRR 1.55, 95% CI 1.55-1.56), while individuals with highest vs. lowest income had 94% vs. 81% primary coverage (adjRR 1.10, 95%CI 1.10-1.10) and 60% vs. 43% booster coverage (adjRR 1.23, 95%CI 1.22-1.24). In the ≥45 y group, individuals with highest vs. lowest education had 96% vs. 92% primary coverage (adjRR 1.02, 95%CI 1.02-1.02) and 88% vs. 80% booster coverage (adjRR 1.09, 95%CI 1.09-1.09), while individuals with highest vs. lowest income had 98% vs. 82% primary coverage (adjRR 1.16, 95%CI 1.16-1.16) and 92% vs. 64% booster coverage (adjRR 1.33, 95%CI 1.33-1.34). In conclusion, we document large socioeconomic inequalities in COVID-19 vaccination coverage, especially for booster vaccination, even though all vaccination was free-of-charge. The results highlight the need to tailor information and to target underserved groups for booster vaccination.