The Delta variant of the COVID-19 virus has prompted new warnings from health officials and even new lockdowns in parts of the world. It’s now the dominant strain in the United States and California. Epidemiologists at UC Davis Health say the threat from this virus mutation highlights the importance of getting vaccinated.

The Delta variant is much more easily transmitted than other variants. “In the United States, it’s making up over 50% of our new cases,” said Lorena Garcia, professor of epidemiology in the Department of Public Health Sciences at the UC Davis School of Medicine. “In some states, it’s making up over 80% of new cases. Viruses are really smart. Their goal is to survive,” Garcia explained.