California COVID-19 strain may be more infectious

Background: Scientists have been monitoring the California variant, known as B.1.427/B.1.429, since its discovery in December.

• And though it's been tracked in most of the U.S. and several other countries, its spread is predominantly in California, unlike the B.1.1.7 variant from the UK, which has spread nationwide.

Driving the news: A study from researchers at University of California, San Francisco, which has not yet been peer reviewed, estimates that cases caused by the variant are now doubling every 18 days.

• Another study showed that people who were infected with the California variant had viral loads twice as high as other patients. It's also possible the variant could lessen the effectiveness of certain antibodies, it said.