Governments across the globe have wasted more than a billion doses of the COVID vaccines, even as many people, including health workers, particularly in low-income countries are yet to get at least a single shot, according to a report.

The report, by science and data analytics company Airfinity, assumed a 10 per cent wastage rate from June 2021 when global dose sharing began. Public reports of vaccine waste and expirations from around the world showed that some 158 million doses have been discarded throughout the world.

Pointing out a significant underreporting of vaccine wastage, the report highlighted a few drugmakers. With 25 million doses, Russia's Sputnik V has the highest wastage figures, followed by AstraZeneca, with claims of 19 million wasted jabs, the report said.

The company noted that of the 14 billion vaccine doses supplied globally to date, 1.1 billion have been wasted and gone unused. Further, the new estimate shows that around 8 per cent of the 1.1 billion doses reportedly disbursed until now have gone unused.

These are within the recommended range of Gavi, the Vaccine Alliance, which assumed the wastage rate for COVID vaccines could be as high as 10 per cent, the report said.

At the same time, the estimates also reflect a certain level of uncertainty toward the under-reporting of vaccine wastage in terms of individual reports from nations' public health systems. "Despite countries' best efforts to avoid wastage, some degree is inevitable," said Dr Matt Linley, analytics director of Airfinity.

"Large multi-dose vials can make efficiencies more challenging, as well as cold chain storage and predicting daily demand or simply a vial being dropped or left out too long. Vaccines in single-dose vials with a longer shelf life, which can be transported and stored more easily, will reduce wastage over time," he added.

Various organisations, including the WHO and UNICEF, had called out countries to share vaccines equitably during the pandemic. Several rich countries also dumped about 100 million COVID-19 vaccines that were near expiry to third-world nations.

"The vaccines were developed with unprecedented public funding and should be global public goods. But instead, vaccine monopolies have concentrated manufacturing and distribution in a handful of countries.

And the needs of developing countries have been treated as an afterthought," said Julia Kosgei, policy advisor to global health campaigners the People's Vaccine Alliance.