[Covid-19 vaccines in times of the Delta variant].

1,5 years into the pandemic, SARS-CoV-2 remains a dynamic and evolving disease. Growing proportions of the population have been vaccinated, but what degree of protection does vaccination actually offer, particularly in the face of an evolving virus and the emergence of viral variants? Here we explore the limits of vaccine protection -providing an overview of emerging data on how well vaccines protect against mild and asymptomatic disease, vaccine effectiveness against the backdrop of variants such as the Delta, and the implications for SARS-CoV-2 transmission. We assess the continued risks for our vulnerable elderly and immune-compromised patient populations, and whether emerging literature should impact our diagnostic strategies.