Syringe shortages could be yet another obstacle in Africa’s Covid vaccination efforts, the W.H.O. warns.

As countries across Africa struggle to vaccinate 1.3 billion people, the continent faces another obstacle besides a lagging supply of doses: the looming likelihood of a shortage of syringes.

“Early next year, Covid-19 vaccines will start pouring into Africa, but a scarcity of syringes could paralyze progress.” Dr. Matshidiso Moeti, the W.H.O.’s regional director for Africa, said at a news briefing. “Drastic measures must be taken to boost syringe production, fast. Countless African lives depend on it.”

Rwanda, South Africa and Kenya have already reported delays in receiving supplies of syringes, according tothe W.H.O.

Covax, a global vaccine-sharing initiative that is working to supply many African countries with doses, is now seeking agreements with syringe manufacturers and trying to plan to keep vaccine deliveries from outpacing the availability of needles.

Africa has the lowest vaccination rate of any continent, and the W.H.O. estimates that about 59 million of continent’s population have been infected with the coronavirus since the beginning of the pandemic, though only somewhat more than eight million cases have been officially recorded.

Unless “drastic measures” are taken to accelerate vaccinations, the organization said, only five African countries are projected to meet the target set by the W.H.O.: fully vaccinating 40 percent of their populations by the end of the year.Most of Africa’s more than 50 countries already missed the W.H.O.’s target of vaccinating 10 percent of their populations by the end of September.

Wealthier countries have monopolized vaccine supplies, creating global inequities in distribution. Those inequities are only likely to be deepened as those same wealthier nations, including the United States, roll out booster campaigns.

By contrast, vaccine deliveries via Covax ground to a halt after India imposed export restrictions on doses as it dealt with its own resurgence this year. In September, regional health experts said that the unpredictability of the limited supply of doses reaching African nations added more obstacles. Some shipments, they said, were within two or three months of expiring — a shelf life too short for some health systems to reliably deploy, and one that many ordinary people interpreted as a signal of poor quality, contributing to vaccine hesitancy.