Length of hospital stay and risk of intensive care admission and in-hospital death among COVID-19 patients in Norway: a register-based cohort study comparing patients fully vaccinated with an mRNA vaccine to unvaccinated patients.

OBJECTIVES: We estimated the length of stay (LoS) in hospital and the intensive care unit (ICU) and risk of admission to ICU and in-hospital death among COVID-19 patients ≥18 years in Norway who had been fully vaccinated with an mRNA vaccine (at least two doses or one dose and previous SARS-CoV-2 infection), compared to unvaccinated patients. METHODS: Using national registry data, we analyzed SARS-CoV-2-positive patients hospitalized in Norway between 1 February and 30 November 2021, with COVID-19 as the main cause of hospitalization. We ran Cox proportional hazards models adjusting for vaccination status, age, sex, county of residence, regional health authority, date of admission, country of birth, virus variant, and underlying risk factors. RESULTS: We included 716 fully vaccinated patients (crude overall median LoS: 5.2 days; admitted to ICU: 103 (14%); in-hospital death: 86 (13%)) and 2487 unvaccinated patients (crude overall median LoS: 5.0 days; admitted to ICU: 480 (19%); in-hospital death: 102 (4%)). In adjusted models, fully vaccinated patients had a shorter overall LoS in hospital (adjusted log hazard ratios (aHR) for discharge: 1.61, 95% CI: 1.24-2.08), shorter LoS without ICU (aHR: 1.27, 95% CI: 1.07-1.52), and lower risk of ICU admission (aHR: 0.50, 95% CI: 0.37-0.69) compared to unvaccinated patients. We observed no difference in the LoS in ICU or in risk of in-hospital death between fully vaccinated and unvaccinated patients. DISCUSSION: Fully vaccinated patients hospitalized with COVID-19 in Norway have a shorter LoS and lower risk of ICU admission than unvaccinated patients. These findings can support patient management and ongoing capacity planning in hospitals.

Increased risk of hospitalisation and intensive care admission associated with reported cases of SARS-CoV-2 variants B.1.1.7 and B.1.351 in Norway, December 2020 -May 2021.

INTRODUCTION: Since their emergence, SARS-CoV-2 variants of concern (VOC) B.1.1.7 and B.1.351 have spread worldwide. We estimated the risk of hospitalisation and admission to an intensive care unit (ICU) for infections with B.1.1.7 and B.1.351 in Norway, compared to infections with non-VOC. MATERIALS AND METHODS: Using linked individual-level data from national registries, we conducted a cohort study on laboratory-confirmed cases of SARS-CoV-2 in Norway diagnosed between 28 December 2020 and 2 May 2021. Variants were identified based on whole genome sequencing, partial sequencing by Sanger sequencing or PCR screening for selected targets. The outcome was hospitalisation or ICU admission. We calculated adjusted risk ratios (aRR) with 95% confidence intervals (CIs) using multivariable binomial regression to examine the association between SARS-CoV-2 variants B.1.1.7 and B.1.351 with i) hospital admission and ii) ICU admission compared to non-VOC. RESULTS: We included 23,169 cases of B.1.1.7, 548 B.1.351 and 4,584 non-VOC. Overall, 1,017 cases were hospitalised (3.6%) and 206 admitted to ICU (0.7%). B.1.1.7 was associated with a 1.9-fold increased risk of hospitalisation (aRR 95%CI 1.6-2.3) and a 1.8-fold increased risk of ICU admission (aRR 95%CI 1.2-2.8) compared to non-VOC. Among hospitalised cases, no difference was found in the risk of ICU admission between B.1.1.7 and non-VOC. B.1.351 was associated with a 2.4-fold increased risk of hospitalisation (aRR 95%CI 1.7-3.3) and a 2.7-fold increased risk of ICU admission (aRR 95%CI 1.2-6.5) compared to non-VOC. DISCUSSION: Our findings add to the growing evidence of a higher risk of severe disease among persons infected with B.1.1.7 or B.1.351. This highlights the importance of prevention and control measures to reduce transmission of these VOC in society, particularly ongoing vaccination programmes, and preparedness plans for hospital surge capacity.

Mismatch between circulating cytokines and spontaneous cytokine production by leukocytes in hyperinflammatory COVID-19.

The disease COVID-19 has developed into a worldwide pandemic. Hyperinflammation and high levels of several cytokines, for example, IL-6, are observed in severe COVID-19 cases. However, little is known about the cellular origin of these cytokines. Here, we investigated whether circulating leukocytes from patients with COVID-19 had spontaneous cytokine production. Patients with hyperinflammatory COVID-19 (n = 6) and sepsis (n = 3) were included at Skåne University Hospital, Sweden. Healthy controls were also recruited (n = 5). Cytokines were measured in COVID-19 and sepsis patients using an Immulite immunoassay system. PBMCs were cultured with brefeldin A to allow cytokine accumulation. In parallel, LPS was used as an activator. Cells were analyzed for cytokines and surface markers by flow cytometry. High levels of IL-6 and measurable levels of IL-8 and TNF, but not IL-1ß, were observed in COVID-19 patients. Monocytes from COVID-19 patients had spontaneous production of IL-1ß and IL-8 (P = 0.0043), but not of TNF and IL-6, compared to controls. No spontaneous cytokine production was seen in lymphocytes from either patients or controls. Activation with LPS resulted in massive cytokine production by monocytes from COVID-19 patients and healthy controls, but not from sepsis patients. Finally, monocytes from COVID-19 patients produced more IL-1ß than from healthy controls (P = 0.0087) when activated. In conclusion, monocytes contribute partly to the ongoing hyperinflammation by production of IL-1ß and IL-8. Additionally, they are responsive to further activation. This data supports the notion of IL-1ß blockade in treatment of COVID-19. However, the source of the high levels of IL-6 remains to be determined.