Background Longer-term consequences after SARS-CoV-2 infection are becoming an
important burden to societies and healthcare systems. Data on post-COVID-19 syndrome in …

Background: The effective reproductive number, R e, is a critical indicator to monitor disease
dynamics, inform regional and national policies, and estimate the effectiveness of …

The immunity conferred by SARS-CoV-2 vaccines and infections reduces the transmission
of the virus. To answer how the effect of immunity is shared between a reduction of …

Background More than two years into the COVID-19 pandemic, most of the population has
developed anti-SARS-CoV-2 antibodies from infection and/or vaccination. However, public …

Background Up-to-date seroprevalence estimates are critical to describe the SARS-CoV-2
immune landscape and to guide public health decisions. Aim We estimate seroprevalence …

BACKGROUND There has been much discussion about coronavirus disease 2019 (COVID-
19) and the virus that causes it, severe acute respiratory syndrome coronavirus 2 (SARS …

Background As vaccination coverage against SARS-CoV-2 increases amidst the emergence
and spread of more infectious and potentially more deadly viral variants, decisions on timing …

Objectives We aimed to prospectively describe the incidence and clinical spectrum of SARS-
CoV-2 infection in immunocompromised paediatric patients in the UK. Methods From March …

Importance Quebec prioritized in-person learning after the first wave of the COVID-19
pandemic, with school closures being implemented temporarily in selected schools or in hot …

Background Serological assays detecting anti-SARS-CoV-2 antibodies are being widely
deployed in studies and clinical practice. However, the duration and effectiveness of the …