For much of the pandemic, the main obstacle to vaccinating the world against the coronavirus was a lack of supply, as wealthy nations bought up vaccine doses and logistical bottlenecks hampered access for the poorest countries.
But increasingly, global vaccination efforts — spearheaded by Covax, a vaccine-sharing initiative backed in part by the World Health Organization — face a problem just as complex: a lack of demand. Backers of Covax say they have seen a sharp decline in dose orders, including in countries with relatively low vaccination rates.
This decline, fueled in part by pandemic fatigue, could prove the biggest obstacle to vaccination initiatives worldwide in the year ahead.