Risk factors for SARS-CoV-2 infection and hospitalisation in children and adolescents in Norway: a nationwide population-based study

Abstract

ObjectiveTo determine risk factors for SARS-CoV-2 infection and hospitalisation among children and adolescents.DesignNationwide, population-based cohort study.SettingNorway from 1 March 2020 to 30 November 2021.ParticipantsAll Norwegian residents<18 years of age.Main outcome measuresPopulation-based healthcare and population registries were used to study risk factors for SARS-CoV-2 infection, including socioeconomic factors, country of origin and pre-existing chronic comorbidities. All residents were followed until age 18 years, emigration, death or end of follow-up. HRs estimated by Cox regression models were adjusted for testing frequency. Further, risk factors for admission to the hospital among the infected were investigated.ResultsOf 1 219 184 residents, 82 734 (6.7%) tested positive by PCR or lateral flow tests, of whom 241 (0.29%) were admitted to a hospital. Low family income (adjusted HR (aHR) 1.26, 95% CI 1.23 to 1.30), crowded housing (1.27, 1.24 to 1.30), household size, age, non-Nordic country of origin (1.63, 1.60 to 1.66) and area of living were independent risk factors for infection. Chronic comorbidity was associated with a slightly lower risk of infection (aHR 0.90, 95% CI 0.88 to 0.93). Chronic comorbidity was associated with hospitalisation (aHR 3.46, 95% CI 2.50 to 4.80), in addition to age, whereas socioeconomic status and country of origin did not predict hospitalisation among those infected.ConclusionsSocioeconomic factors, country of origin and area of living were associated with the risk of SARS-CoV-2 infection. However, these factors did not predict hospitalisation among those infected. Chronic comorbidity was associated with higher risk of admission but slightly lower overall risk of acquiring SARS-CoV-2.

Time course of adverse reactions after BNT162b2 vaccination in healthy and allergic disease individuals aged 5–11 years: an observational and historical cohort study

“…The higher frequency of adverse reactions in those with allergic diseases was consistent with previous reports on adults [39]. It has been suggested that individuals with allergic diseases, such as asthma, who are potentially susceptible to COVID-19 [8; [25][26][27][28][29], may experience more adverse reactions after BNT162b2 vaccination. Therefore, to ensure that children with allergic diseases, receive the vaccine safely, further information regarding adverse reactions and long-term effects of BNT162b2 vaccination needs to be collected.…”

“…Adverse reactions in this population were generally non-serious, more common after second vaccination, and substantially less common than those observed among individuals aged 12-15 years [22][23][24]. Children with underlying comorbidities are at risk of severe COVID-19 [8; [25][26][27][28][29]; however, long-term data on the adverse reactions after BNT162b2 vaccination in these patients are limited. Fukushima Prefecture, Japan began administering BNT162b2 as two doses (10 µg, 0.2 mL each), three weeks apart to individuals aged 5-11 years on March 9, 2022.…”

When schools were open for in-person teaching during the COVID-19 pandemic - the nordic experience on control measures and transmission in schools during the delta wave

“…Transmission of SARS-CoV-2 in schools has been a prevailing concern during the pandemic, resulting in extensive measures in schools and limited access to education for millions of children and adolescents [ 1 ]. School closure has been frequently used to prevent in-school transmission, although children and adolescents have very low risk for severe disease from SARS-CoV-2 infection [ 2 – 6 ]. School closures have profound negative consequences for students’ learning, wellbeing and mental health [ 7 – 9 ], and has not been found more effective to reduce COVID-19 transmission than in-person teaching with mitigation measures [ 10 – 14 ].…”

“…The measures, with slight variations between countries, included stay-home-when-sick policy, hygiene measures, testing of close contacts, isolation of positive cases, limited use of quarantine for school contacts, and very limited use of distance measures and face masks. The decision to offer full in-person teaching was additionally based on the low severity of disease in children [ 2 – 6 ] and on evidence showing that transmission in schools was limited [ 10 , 32 – 34 ]. Furthermore, all the Nordic countries initiated vaccination of adolescents before or around start of the semester, but timing of initiation and implementation in different age groups varied between the countries.…”

Time course of adverse reactions following BNT162b2 vaccination in healthy and allergic disease individuals aged 5–11 years and comparison with individuals aged 12–15 years: an observational and historical cohort study

“…The higher frequency of adverse reactions in those with allergic diseases was consistent with previous reports on adults [ 40 ]. It has been suggested that individuals with allergic diseases, such as asthma, who are potentially susceptible to COVID-19 [ 8 , 25 – 29 ], may experience more adverse reactions after BNT162b2 vaccination. Therefore, to ensure that children with allergic diseases receive the vaccine safely, further information regarding adverse reactions and long-term effects of BNT162b2 vaccination needs to be collected.…”