Variants! The Shape-Shifting Challenge of COVID-19 by internationally recognized infectious disease scientist and COVID-19 expert, William A. Haseltine, PhD. Variants! The Shape-Shifting Challenge of COVID-19 by William A. Haseltine, PhD. New Book on COVID-19 Variants from Internationally Recognized Expert Answers Important Questions About Our Future As the world moves into the second year of the COVID-19 pandemic, SARS-CoV-2 variants are now a fundamental issue. Understanding virus variation is critical to understanding how the pandemic will unfold and how COVID-19 may continue to affect the global economy, society, and individuals. This new book from one of the world's leading experts answers questions on many minds, such as: