India on Monday has begun a nationwide campaign of providing free COVID-19 vaccines for all adults.

The nationwide campaign of providing free COVID-19 vaccines for all adults came into effect after weeks of criticism that a chaotic rollout had caused acute shortages and intensified a deadly second wave that killed hundreds of thousands in April and May.

Earlier this month, Prime Minister Narendra Modi reversed a policy under which states made their own purchases from drug makers and along with private hospitals were administering doses to people aged 18-45. And as most states shut down vaccination centers for the younger population citing shortages, a majority turned to private hospitals that charged between $9-$24 a dose, and supply gaps widened between urban and rural areas.

Under the federal campaign to inoculate all adults for free India gave out a record, 7.5 million vaccine doses on Monday itself.

Meanwhile, experts have warned of a potential third wave as only about 5% of all 950 million eligible people are fully inoculated with two doses even as daily infections have fallen this month. As most cities have begun lifting lockdown curbs, experts have cautioned that a swift reopening could complicate a vaccination program that needs to be at least four times faster.