A massive virus surge in March pushed India’s health systems to the breaking point:

Aniruddha Ghosal, Associated Press

Starting Monday, every Indian adult can get a COVID-19 vaccine dose for free that was purchased by the federal government.

The policy reversal, announced by Prime Minister Narendra Modi last week, ends a complex system of buying vaccines that worsened inequities in administering the shots. India is a key supplier of vaccines around the world, and its missteps have left millions of people waiting unprotected. Only about 3.5% of Indians are fully vaccinated and while the policy change is likely to address inequality, questions remain. Moreover poor planning means vaccine shortages will continue.

Here’s a look at the changes to India’s vaccine policy and what it means:

A massive virus surge in March pushed India’s health systems to the breaking point: Hundreds of thousands of people were newly infected each day, hospitals overflowed with patients gasping for air and nighttime skies glowed as busy crematories burned bodies in the open air.

At the time, India was vaccinating those most vulnerable for free, but states flagged shortages. Vaccinations were opened to all adults in May, but Modi’s government switched from taking the lead on vaccine availability to try to get them distributed to where they were most needed.

Instead, the federal government would buy half of all vaccines made and would continue giving free shots to 300 million health care and frontline workers, along with those older than 45. States and private hospitals would split the remaining shots to vaccinate over 600 million adults younger than 45.

However, experts warned that vaccine makers might prioritize sales to the private sector to reap more profits. One state health minister said the Serum Institute of India, which is making the AstraZeneca vaccine mostly used in India, wouldn’t respond to the state’s inquiries.

India has one of the largest immunization programs in the world and each year 300 million shots are given to infants and mothers.

But states have never bought vaccines before. And a limited supply meant states were competing with each other, while paying a higher prices than what the federal government could have negotiated, said Dr. Chandrakant Lahariya, a health policy expert.

“That essentially makes it inefficient,” he said.

When India started vaccinations, it aimed to prioritize health workers, essential workers and older people. But expanding the criteria despite shortages created inequity. Since May, more people younger than 45 have received their first shot than those older than 60. More than 74 million people older than 60 remain unvaccinated.

Modi said these decisions were taken to accommodate states, but the fractured response may have cost lives, said Dr. Vineeta Bal, who studies immune systems at the Indian Institute of Science Education and Research in Pune city.

The federal government said it will buy 75% of all vaccines made by Indian vaccine makers and likely renegotiate prices. These shots will now be given to states to be distributed for free. Private hospitals can buy the remaining 25% at prices that have been capped.

States will receive the vaccines based on their population, disease burden and how many people have been vaccinated, while wasted doses will be penalized.

But the biggest challenge will be to ensure a continuous supply. Delhi chief minister Arvind Kejriwal, for instance, said, “Where will the vaccines come from is a big question.”

India booked 300 million shots of vaccine candidate Biological E. for $205.62 million in its first agreement to book shots in advance. But it is still being tested and hasn’t been approved, so likely won’t make a difference to supplies until later this year.

And with only one such deal made so far, experts don’t think India’s reliance on its existing, overstretched suppliers like Serum Institute will end soon.

Meanwhile, private hospitals don’t yet know how they will procure vaccines under the new policy, and some say they’re unlikely to continue organizing neighborhood vaccine drives since prices had been capped.