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.

Unexpected vaginal bleeding and COVID-19 vaccination in nonmenstruating women.

The association between coronavirus disease 2019 (COVID-19) vaccination and vaginal bleeding among nonmenstruating women is not well studied. The Norwegian Institute of Public Health followed several cohorts throughout the pandemic and early performed a systematic data collection of self-reported unexpected vaginal bleeding in nonmenstruating women. Among 7725 postmenopausal women, 7148 perimenopausal women, and 7052 premenopausal women, 3.

Heavy bleeding and other menstrual disturbances in young women after COVID-19 vaccination.

Background: Many signals of menstrual disturbances as possible side effects of vaccination against COVID-19 have been reported. Our objective was to compare the risk of menstrual disturbances before and after vaccination among women aged 18-30 years in Oslo, Norway.

Methods: We used electronic questionnaires to collect reports of menstrual disturbances from 3972 women aged 18-30 years, participating in the population-based Norwegian Young Adult Cohort.

Determinants of humoral and cellular immune responses to three doses of mRNA SARS-CoV-2 vaccines in older adults: a longitudinal cohort study.

Background: Older age is associated with poorer outcomes to COVID-19 infection. The Norwegian Institute of Public Health established a longitudinal cohort of adults aged 65-80 years to study the effects of the COVID-19 pandemic. Here we describe the characteristics of the cohort in general, and specifically the immune responses at baseline and after primary and booster vaccination in a subset of longitudinal blood samples, and the epidemiological factors affecting these responses.