On day four of a pan-India lockdown to counter the spread of COVID-19, a big concern is shortage of ventilators, which are critical for treating pneumonia, a primary cause of death among COVID-19 patients. Imports of ventilators, their components and other medical equipment have been disrupted due to lockdowns in other nations too. With ventilators emerging as the biggest need of the hour, the Defence Research and Development Organisation (DRDO) is now stepping in. The DRDO chief Dr G Satheesh Reddy said a plan is underway to develop and produce along with the industry 5,000 ventilators per month as early as three months from now.