A relationship between the infecting dose and the risk of disease severity has not been demonstrated for SARS-CoV-2 infection. Here, we report three clusters of individuals that were potentially exposed to distinct inoculum ...

The recent emergence of a novel coronavirus (severe acute respiratory syndrome coronavirus 2) has caused a pandemic, which is the most severe infectious disease outbreak in many decades. Other infective agents such as ...

Background: The emergence and rapid global spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a major challenge to health services, and has disrupted social and economic activities worldwide. ...

A third wave of COVID-19 occurred after Christmas 2020 in Madrid, one of the European pandemic epicenters. We noticed 6 major differential features to previous waves. First, household contacts were a large proportion of ...

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has hit health-care systems and societies in an unprecedented manner. In 1981, the first cases of AIDS were reported and wide diagnostic ...