Vaksinasjonsdekning mot covid-19 etter fødeland og underliggende risiko for alvorlig sykdomsforløp.

Background: Support for the COVID-19 vaccination programme has been high in Norway throughout the pandemic, but previous studies have observed variation based on country of birth. If the unvaccinated are young and healthy, the risk and consequences for the individual and for the health service will be less than if the unvaccinated have underlying risk of severe COVID-19. The purpose of the study was to examine the degree to which vaccination coverage varied by country of birth in persons with and without underlying risk. Material and method: We used the Norwegian emergency preparedness register Beredt C19 to link vaccination coverage to demographic and health variables. Using Poisson regression, we estimated the relative likelihood of being vaccinated for foreign-born individuals compared to Norwegian-born individuals, for those with and without underlying risk of severe COVID-19, adjusted for sex, age, level of education, household income and county. Results: The study population was 4 304 249, which included 768 312 people who were born outside Norway. The vaccination coverage varied in total from 47 to 94 % between countries of birth. The variation between countries of birth was less in the group with underlying risk, ranging from 63 to 96 %. The difference between persons with and without an underlying risk was most pronounced among those born in Poland (RR 0.71 and 0.55) and Lithuania (RR 0.69 and 0.61). In absolute numbers, this corresponded to a difference in relative risk of 0.16 and 0.08, respectively. Interpretation: Higher vaccination coverage against COVID-19 among persons with an underlying risk means that the variation between countries of birth may have had less serious implications in terms of severe clinical course and healthcare needs than previously assumed.

Impact of Omicron on sick leave across industries: A population-wide study.

AIMS: To estimate the industry-specific impact of the COVID-19 pandemic (Omicron wave) on sick leave. METHODS: Using individual-level data from the Norwegian Emergency Preparedness Register, the study covers all workers in different industries (N = 2,733,751 people) on a monthly level in the time periods January-March 2017-2020 (except March 2020) and 2022 (38,199,536 person-months). We estimated the industry-specific increase in monthly average sick leave during the Omicron wave in 2022 compared with the corresponding months in 2017-2020. RESULTS: We found an average increase in monthly sick leave rates of 2.92 percentage points (95% CI 2.9-2.94) during the three first months of 2022. The increases were strongest within food and accommodation (4.42 percentage points increase, 95% CI 4.33-4.51) and administrative support services (3.94 percentage points increase, 95% CI 3.85-4.03). CONCLUSIONS: The Omicron wave resulted in a substantial increase in sick leave, which was unevenly distributed across industries. The results of this study highlight the importance of industry-specific contingency planning when facing the rapid spread of infectious diseases.

Has vaccination alleviated the strain on hospitals due to COVID-19? A combined difference-in-difference and simulation approach.

BACKGROUND: Serious measures, including mass vaccination, have been taken to ensure sufficient hospital capacity during the COVID-19 pandemic. Due to high hospitalization risk in the oldest age groups, most countries prioritized elderly for vaccines. The aim of this study is to broaden the understanding of how vaccination in younger age groups relieved the strain on hospitals during the pandemic. METHODS: To determine the impact of vaccination on hospitalization, we relied on individual level data on health care use and vaccination from the Norwegian Emergency Preparedness Register Beredt C19. Using a pre-post design, we estimated the increase in hospitalization days from before to after confirmed COVID-19 for individuals aged 18-64 who were fully vaccinated (N=2 419) or unvaccinated (N=55 168) with comparison groups of vaccinated (N=4 818) and unvaccinated (N= 97 126) individuals without COVID-19. To evaluate whether vaccination itself contributed to a strain in hospitals, we use a similar design to study hospitalization rates before and after vaccination by comparing individuals vaccinated with the first dose (N=67 687) to unvaccinated individuals (N=130 769). These estimates were incorporated into a simulation of hospitalization days with different vaccine scenarios to show how the estimated results might have mattered for the hospitals and their capacity. RESULTS: Hospitalization days increased by 0.96 percentage point each day during the first week and 1.57 percentage points during the second week after testing positive for COVID-19 for unvaccinated individuals. The corresponding increase was 0.46 and 0.32 for vaccinated individuals, i.e., a substantial difference. The increase was significantly higher for those aged 45-64 than for those aged 18-25. We find no increase in hospitalization days due to vaccination. Simulation results show that vaccination reduced hospitalization days by 25 percent, mainly driven by age 45-64. CONCLUSION: Our findings indicate that vaccination of individuals aged 18-64 did alleviate pressure on hospitals. Whereas there was a substantial relieve from vaccinating the 45-64 age group, there was no such contribution from vaccinating the 18-25 age group. Our study highlights how simulation models can be useful when evaluating alternative vaccine strategies.

General practitioner visits after SARS-CoV-2 omicron compared with the delta variant in children in Norway: a prospective nationwide registry study.

BACKGROUND: SARS-CoV-2 infection in children is followed by an immediate increase in primary care utilisation. The difference in utilisation following infection with the delta and omicron virus variants is unknown. OBJECTIVES: To study whether general practitioner (GP) contacts were different in children infected with the omicron versus delta variant for up to 4 weeks after the week testing positive. SETTING: Primary care. PARTICIPANTS: All residents in Norway aged 0-10. After excluding 47 683 children with a positive test where the virus variant was not identified as delta or omicron and 474 children who were vaccinated, the primary study population consisted of 613 448 children. MAIN OUTCOME MEASURES: GP visits. METHODS: We estimated the difference in the weekly share visiting the GP after being infected with the delta or omicron variant to those in the study population who were either not tested or who tested negative using an event study design, controlling for calendar week of consultation, municipality fixed effects and sociodemographic factors in multivariate logistic regressions. RESULTS: Compared with preinfection, increased GP utilisation was found for children 1 and 2 weeks after testing positive for the omicron variant, with an OR of 6.7 (SE: 0.69) in the first week and 5.5 (0.72) in the second week. This increase was more pronounced for children with the delta variant, with an OR of 8.2 (0.52) in the first week and 7.1 (0.93) in the second week. After 2 weeks, the GP utilisation returned to preinfection levels. CONCLUSION: The omicron variant appears to have resulted in less primary healthcare interactions per infected child compared with the delta variant.