Ongoing Battle Against COVID-19 Aided by Variant Tracking, Better Understanding of Viral Evolution [Source: vchal/Getty Images] As more people become vaccinated against SARS-CoV-2, the virus that causes COVID-19, there is movement to resume normal every day activities. But many things still remain uncertain about the virus. Will it be tamed by the current array of vaccines? Or will these vaccines fail to keep pace with fast-evolving SARS-CoV-2 variants? And even if vaccines succeed initially, will they continue to protect us over the long term? Questions such as these are unavoidable because SARS-CoV-2, like any other virus, will change ceaselessly to fulfill its sole purpose: survival. Essentially, SARS-CoV-2 has us caught between hope and worry—as dramatized by this article’s sidebar (see “The Temper of the COVID-19 Response, in Three Quotes”).