Nine months after launching what it called "the world's biggest vaccination drive", India is set to complete 1 billion or 100 crore doses today. India launched the vaccination drive on January 16, first for frontline and healthcare workers. On March 1, the vaccination drive was opened for vulnerable groups — all above 60 years and those above 45 years with comorbidities. This was then changed to all above 45 years on April 1. And on May 1, India expanded its vaccination coverage to include all above 18 years. The Centre is set to mark the day with numerous events, including the release of a song and an audio visual film by Central Health Minister Mansukh Mandaviya at Red Fort . The government will hail the event as #VaccineCentury on social media. Meanwhile, in the run-up to the one billion vaccine mark, the government has renewed its emphasis on administration of the second dose. For the past one week, the trend of first doses exceeding the second has been reversed.Union Health Minister Mansukh Mandaviya appealed to all those who are eligible to get inoculated without delay and contribute to the "historic" journey. The administering of one billion vaccine doses - given the unknown and unpredictable nature of the coronavirus, the scale and intensity of the pandemic, and the challenges surrounding manufacturing, distribution, and delivery - represents a significant effort on the part of the government.