But the head of the world's largest vaccine manufacturer, India's Serum Institute, said in an interview that the country's vaccine shortage will likely last months. Though India's current outbreak is the largest ever seen, it isn't the only country reporting another wave – Iran, Brazil, Colombia and Turkey have all seen recent spikes in their daily death tolls, according to data from Johns Hopkins University. Even if one country is fully vaccinated, transmission in another country could produce variants that evade vaccinations.