Poor countries refused to take around 100 million donated Covid-19 vaccine doses in December alone, chiefly due to their short shelf life, the United Nations said Thursday.
The World Health Organization (WHO) has slammed the deadly "moral shame" of high-income countries hogging vaccine supplies then offloading near-expiry doses to jab-starved poorer nations.
Stark images last month of Nigeria disposing of more than a million AstraZeneca doses that had gone off highlighted the issue.
Unicef, the UN Children's Fund, uses its vaccine logistics expertise to handle delivery flights for Covax, the global scheme set up to ensure a flow of doses to poorer nations.
In December, "we had almost more than 100 million doses that have been refused because of countries' capacities", Unicef's supply division director Etleva Kadilli told a European Parliament committee.
"The majority of refusals are due to product shelf life."
- Short notice -
"The short shelf life is really creating a major bottleneck for countries to plan their vaccination campaigns," Kadilli explained.
"Until we have a better shelf life, this is going to be a pressure point for the countries, specifically when countries want to reach populations in hard-to-reach areas."
European Union donations account for a third of the doses delivered so far via Covax, Kadilli told lawmakers.
In October-November, 15 million EU-donated doses were rejected -- 75% of them AstraZeneca shots with a shelf life of less than 10 weeks upon arrival.
Kadilli said that several nations were requesting for deliveries to be put off until after March, when they might be better able to handle the pressure on the cold storage chain.
Many countries "come back and request split shipments -- they want to push doses towards the next quarter", she said.
"And I'm talking here also for large, big countries where naturally you'd think that they do have the capacity."
Covax is co-led by the WHO, the Gavi vaccine alliance, and CEPI, the Coalition for Epidemic Preparedness Innovations. Via Unicef, it is about to deliver its billionth vaccine dose.
On 29 December, the WHO announced that 92 of its 194 member states had missed its target of vaccinating 40% of their population by the end of 2021.
"This is due to a combination of limited supply going to low-income countries for most of the year and then subsequent vaccines arriving close to expiry and without key parts like the syringes," said WHO chief Tedros Adhanom Ghebreyesus.
"It's not only a moral shame; it cost lives."
In a speech on Thursday, he said that while more than 9.4 billion vaccine doses had been administered around the world, more than 85% of people in Africa are yet to receive a single dose.
"Some of the supply constraints we faced last year are now starting to ease, but we still have a long way to go to reach our target of vaccinating 70% of the population of every country by the middle of this year," Tedros told member states.