A string of nations across Africa and Asia have run out of COVID-19 vaccines or are on the brink of doing so, months after receiving first shipments from a global program meant to equitably distribute the lifesaving shots.

When the supplies arrived in developing countries earlier this year through the Covax effort, they were seen as an important step in narrowing a glaring gap in access. Today, many of those same countries are facing vaccine shortages and are unsure when they will receive donations from wealthy countries.

A World Health Organization adviser on Monday said that of 80 lower-income countries across the globe that have received vaccines through the program, about 40 are either out of vaccines or on the verge. 

“Well over half of countries have run out of stock and are calling for additional vaccine,” the adviser, Bruce Aylward, told reporters. “But in reality it's probably much higher."

In the race to end the pandemic, it’s vaccine against virus. Slowdowns in inoculation programs can leave room for problematic new variants to emerge that could reignite infection counts or put already vaccinated people back at risk. Countries without rich health budgets can be forced onto the more-expensive private market. And if supplies don’t get restocked, vulnerable populations of older people and health workers can be left only partially vaccinated while awaiting the delivery of second doses.

Seven countries in Africa, including Ivory Coast, Gambia and Kenya, have used all of their Covax stocks, according to the WHO, while others in Asia, Latin America and beyond are at risk of exhausting their supplies. In response, many are slowing or halting vaccine programs while they await new shipments or look for alternate sources.

Covax was set up last year to ensure equitable access to vaccines, and was organized by the nonprofit Gavi, the Vaccine Alliance, another group known as CEPI, or the Coalition for Epidemic Preparedness Innovations, and the WHO. It established a global purchasing and distribution pool, particularly for less-wealthy nations that were unable to strike large pre-purchase deals or manufacture their own vaccines.

Its goal is to deliver 1.8 billion doses to more than 90 lower-income economies by early 2022. So far, it has shipped only 88 million — about as many as the number of doses already administered in the U.S. states of California, Texas and New York, according to Bloomberg’s Vaccine Tracker. The program is heavily reliant on AstraZeneca Plc’s two-dose vaccine, but has been hamstrung by delays in shipments from a key manufacturer of those shots, the Serum Institute of India, after the country halted exports to tackle a devastating outbreak at home.

Read more: Serum Institute’s Problems Keep World Short of Covid Shots

In Africa, Ivory Coast has used about 730,000 doses of AstraZeneca’s vaccine and is now relying on about 100,000 doses of the Pfizer Inc. vaccine it received last week. The country is looking to acquire millions of additional doses to maintain public faith in the program and ensure it can complete protection for those who received the initial dose.

In Ghana and Ivory Coast, the start of Covax rollouts on March 1 marked a key moment that Unicef Executive Director Henrietta Fore called a “hopeful light at the end of the tunnel.” Ghana has since used more than 90% of its doses. While the country has signed pacts with a number of suppliers, including an agreement for Russia’s Sputnik V vaccine, supply challenges have hampered deliveries. Another West African country, Gambia, said last week it has run out of AstraZeneca shots. The country is turning to Sinopharm Group Co. and plans to introduce the Chinese company’s vaccine next month.

Elsewhere in Africa, Eswatini, Lesotho, Malawi and Rwanda have exhausted all the vaccines they received through Covax. Seven more, including Angola, Uganda, Ethiopia and Egypt, have used more than 80% of supplies, according to the WHO. 

It’s not just an issue in Africa. Vaccination has slowed to a crawl in Bangladesh, and the government has turned to China and Russia to secure more supplies. Sri Lanka is awaiting health ministry approval to give people Pfizer’s vaccine as the second dose amid a shortfall in AstraZeneca shots.

In Nepal, supply shortages have slowed the vaccine program, and the country has managed to fully vaccinate less than 3% of the population. 

“Vaccination to the entire population is a dream that is quite far off,” said Tara Nath Pokhrel, the family welfare director at Nepal’s health ministry.

WHO Director-General Tedros Adhanom Ghebreyesus has welcomed the donation of vaccines from wealthy countries, but has also urged them to increase and accelerate their contributions to help regions confronting a surge in cases. The Group of Seven earlier this month pledged to donate vaccine doses to developing nations, while President Joe Biden announced that the U.S. would begin shipping a half-billion donated doses of Pfizer vaccines to countries in “dire need” in August. On Monday, the U.S. delayed a separate shipping target for 80 million donated vaccine doses, many of which are meant for developing nations.

Many of the nations running short face another problem: After giving the first dose of shots to priority populations like the elderly or health workers, they’re not receiving enough to give the second shot, Kate O’Brien, who heads the WHO’s vaccination division, told reporters last week. 

“They just don’t have more doses that are coming at this point,” O’Brien said.

A huge number of countries will need to suspend second doses, Aylward, the WHO adviser, said last week. Countries including Nepal and Sri Lanka are “very desperate in trying to access doses,” he said. “We have quite a substantial problem.”

Vaccine Gap

The supply shortages have exacerbated vaccine inequality. Wealthy countries have administered 68 doses per 100 people on average, compared with just 2 doses per 100 in Africa, according to the WHO. Disease experts have warned that as long as the coronavirus continues to circulate widely, it will have more opportunities to mutate into new variants that could be more transmissible or evade vaccines.

The delta variant, the fast-spreading version first identified in India, has been reported in 14 African countries, and Covid cases across the continent are nearing the peak of more than 120,000 weekly cases seen in July 2020.

Supply uncertainty could undermine confidence in vaccine programs in countries that are struggling to fight COVID-19 on top of other health threats.

“It takes so much effort to put in place a vaccination program, it doesn’t help peoples’ trust in their government and health systems,” said Els Torreele, a health researcher at University College London. “You’re talking about countries where there’s already a lot of fragility.”

Other countries in Africa face a different dilemma and are grappling with logistics challenges, hesitancy and misinformation. Almost two dozen nations have used less than half of the doses they have received so far, and almost 1.3 million AstraZeneca doses in 18 countries must be used by the end of August to avoid expiration, according to the WHO.

“It’s not just having the vaccines, it’s rolling them out,” Torreele said. “In poor countries they may not have additional money for that.”