New COVID-19 booster shots from Pfizer and BioNTech have cleared all regulatory hurdles in time for the expected winter surge of the virus.

The new vaccine aims specifically to prevent further infection of omicron, which over the past 10 months has spread to become the dominant COVID-19 variant circulating around the world. Notably, the booster shot relies on mRNA technology, which researchers before the COVID-19 pandemic saw as a promising epidemiological tool. The mRNA technology, when working correctly, teaches human cells how to make a protein that will trigger an immune response inside a person’s body.