Trends in childhood asthma in Denmark, Finland, Norway and Sweden.

Aim: Estimate the incidence of asthma among children aged 0 to 15 years in Denmark, Finland, Norway and Sweden during 2000-2017.

Methods: Cases of preschool asthma (up to 6 years) and school-age asthma (from 6 years) were identified through national registers using an algorithm including hospital diagnoses and prescription medicines. The respective cumulative incidence (CI) was estimated in 1-year age intervals for each country and birth year.

Vaccination against measles-mumps-rubella and rates of non-targeted infectious disease hospitalisations: Nationwide register-based cohort studies in Denmark, Finland, Norway, and Sweden.

Objectives: To investigate if receipt of measles-mumps-rubella (MMR) vaccine following the third dose of diphtheria-tetanus-acellular pertussis (DTaP3) is associated with reduced rates of non-targeted infectious disease hospitalisations.

Methods: Register based cohort study following 1,397,027 children born in Denmark, Finland, Norway, and Sweden until 2 years of age. Rates of infectious disease hospitalisations with minimum one overnight stay according to time-varying vaccination status were compared using Cox proportional hazards regression analysis with age as the underlying timescale and including multiple covariates.

Post-COVID symptoms after SARS-CoV-2 omicron infection and the effect of booster vaccination: A population-based cohort study.

Background: The impact of vaccination on the type and risk of specific post-COVID symptoms after Omicron infection is not clear. We aimed to investigate the excess risk and patterns of 22 symptoms 3-5 months after Omicron infection, comparing uninfected and infected subjects with and without recent booster vaccination.

Methods: We conducted a population-based prospective study based on four questionnaire-based cohorts linked to national health registries.

Infectious disease hospitalization after receipt of human papillomavirus vaccine: a nationwide register-based cohort study among Danish, Finnish, Norwegian, and Swedish girls.

It has been suggested that non-live vaccines may increase susceptibility to non-targeted infections and that such deleterious non-specific effects are more pronounced in girls. We investigated whether receipt of non-live vaccine against human papillomavirus (HPV) was associated with increased risk of infectious disease hospitalization. A nationwide cohort study based on detailed individual-level data from national registries was performed in Denmark, Finland, Norway, and Sweden.

Is vaccination against measles, mumps, and rubella associated with reduced rates of antibiotic treatments among children below the age of 2 years? Nationwide register-based study from Denmark, Finland, Norway, and Sweden.

Objectives: Previous studies have shown that vaccination against measles, mumps, and rubella (MMR) may have beneficial non-specific effects, reducing the risk of infections not targeted by the vaccine. We investigated if MMR vaccine given after the third dose of diphtheria-tetanus-acellular pertussis vaccine (DTaP3), was associated with reduced rates of antibiotic treatments.

Methods: Register-based cohort study following children from the age of recommended MMR vaccination until age 2 years.