Background The global surge in the omicron (B. 1.1. 529) variant has resulted in many
individuals with hybrid immunity (immunity developed through a combination of SARS-CoV …

The clinical course and outcome of COVID-19 are highly variable, ranging from
asymptomatic infections to severe disease and death. Understanding the risk factors of …

The largest burden of COVID-19 is carried by the elderly, and persons living in nursing
homes are particularly vulnerable. However, 94% of the global population is younger than …

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection has brought
new challenges to the global prevention and control of coronavirus disease 2019 (COVID …

We are reviewing the current state of knowledge on the virological and immunological
correlates of long COVID, focusing on recent evidence for the possible association between …

Background Although the COVID-19 pandemic has persisted for over 3 years, reinfections
with SARS-CoV-2 are not well understood. We aim to characterize reinfection, understand …

Background SARS-CoV-2 positive pregnant women are at higher risk of adverse outcomes,
but little evidence is available on how variants impact that risk. We aim to evaluate maternal …

The impact of vaccination on SARS-CoV-2 infectiousness is not well understood. We
compared longitudinal viral shedding dynamics in unvaccinated and fully vaccinated adults …

Background China witnessed a surge of Omicron infections after abandoning 'zero
COVID'strategies on 7 December 2022. The authorities report very sparse deaths based on …

SARS-CoV-2-specific T cell response has been proven essential for viral clearance, COVID-
19 outcome and long-term memory. Impaired early T cell-driven immunity leads to a severe …