Gisselle Vila Benites, University of Melbourne and Anthony Bebbington, Clark University

Peru’s new interim president took office on Nov. 17 under unenviable circumstances.

Francisco Sagasti became the South American country’s third president in a week after President Martin Vizcarra was impeached for “moral incapacity” in what many Peruvians saw as a coup by Congress. Then Vizcarra’s successor, congressional president Manuel Merino, was quickly forced to resign after furious public protest.

 Moderna’s new mRNA vaccine is almost 94.5% effective in large-scale trials.

Sanjay Mishra, Vanderbilt University

As the weather cools, the number of infections of the COVID-19 pandemic are rising sharply. Hamstrung by pandemic fatigue, economic constraints and political discord, public health officials have struggled to control the surging pandemic. But now, a rush of interim analyses from pharmaceutical companies Moderna and Pfizer/BioNTech have spurred optimism that a novel type of vaccine made from messenger RNA, known as mRNA, can offer high levels of protection by preventing COVID-19 among people who are vaccinated.