There is no end in sight to the ongoing coronavirus pandemic, as new, more dangerous variants like the Delta variant continue to emerge.
Several highly effective vaccines have been developed, however, which has changed the course of the pandemic, potentially saving millions of lives.
Though even fully vaccinated people can get sick with COVID-19 -- because Delta and other new variants can evade antibodies -- they are still thought to be protected from hospitalization and death.
But for how long? New research sheds some light on this and other questions.