Nosocomial Transmission of SARS-CoV-2 Involving Vaccinated Health Care Workers.

COVID-19 vaccination has proven to be effective at preventing symptomatic disease but there are scarce data to fully understand whether vaccinated individuals can still behave as SARS-CoV-2 transmission vectors. Based on viral genome sequencing and detailed epidemiological interviews, we report a nosocomial transmission event involving two vaccinated health care-workers (HCWs) and four patients, one of them with fatal outcome. Strict transmission control measures, as during the prevaccination period, must be kept between HCWs and HCWs-patients in nosocomial settings.

High SARS-CoV-2 viral load in travellers arriving in Spain with a negative COVID-19 test prior to departure.

Hundred and ninety-six travellers with negative-COVID-19-tests prior to departure tested positive, on arrival at Madrid (April/June 2021), from a total of 45 211 travellers tested (0.43%). Viral loads (Ct: 20.

SARS-CoV-2 B.1.1.7 Decline Is Not Driven by the Introduction of a More Successful Variant.

The SARS-CoV-2 variant of concern (VOC) Delta (B.617.2 lineage) displaced the predominant VOC Alpha (B.