3D print of a spike protein of SARS-CoV-2, the virus that causes COVID-19–in front of a 3D print of a SARS-CoV-2 virus particle. The spike protein (foreground) enables the virus to enter and infect human cells. On the virus model, the virus surface (blue) is covered with spike proteins (red) that enable the virus to enter and infect human cells. Credit: NIH

A single dose of the Pfizer vaccine provides “very high” protection from COVID-19 after 21 days—without a ‘top up’ dose in the recommended time frame, according to a new study from the University of East Anglia.

Researchers looked