Coronavirus researchers need the right genetically engineered mice to test potential vaccines. But most of these mice have been on ice. One lab is breeding a new generation of mice to meet the demand.
Alternative tests are emerging, the agency says, such as computer modeling and tissue studies of cells grown in the lab. Environmental advocates say the move is too quick, and disregards human health.
Scientists infected the cats with toxoplasmosis and later killed them. Bipartisan members of Congress complained about the practice and the agency ended the program.
