Also: the how and why of face masks, and the high cost of getting high in California 

Coronavirus: First patients injected in UK vaccine trial 

(Fergus WalshBBC, 4/23/20) 

The first patients in an Oxford University vaccine trial for coronavirus were injected this week. The vaccine, like several others that have been proposed, targets the spike proteins on the surface of the SARSCoV2 virusA control group was injected with a vaccine for meningitis. The study prioritized volunteers in the health care industry, as they are more likely to be exposed to the virus. Researchers will compare infection rates among those who received the virus against the general population, but a downturn in cases in the UK may delay results. 

All your questions about how to wear a face mask — answered 

(Kristen RogersCNN, 4/24/20) 

The article discusses the nuances of wearing face coverings to prevent the spread of COVID-19, as recommended by the US Centers for Disease Control and Prevention. The recommendation is based on evidence suggesting the spread of the disease from asymptomatic people. Though proper medical grade masks are not recommended for the public due to shortages, the CDC advocates wearing surgical masks or reusable cloth masks in public. 

Costs of cannabis testing compliance: Assessing mandatory testing in the California cannabis market 

(Pablo Valdes-Donoso et. al., PLOS ONE, 4/23/20) 

According to researchers at the University of California, Davis, the cost of testing legal cannabis in California could be as high as 10% of the wholesale retail price. They note that the acceptable safety levels for various contaminants, including pesticides, are much more stringent than for other agricultural products. The researchers warn that the high cost of legal cannabis in California could turn consumers to illegal sources. 

—Stories compiled by Senior Scientific Writer Mary Parker