Belgium will receive only half the doses of United States drugmaker Pfizer vaccine it ordered for January because of a logistical difficulty that occurred last month.

Health Ministry spokesman Yves Van Laethem said a logistical issue in the second half of December prevented the delivery of the vaccines as planned in the Belgian vaccination strategy, without detailing the problem.

This first phase of vaccination will continue as planned with two doses being injected. “It was decided to continue a complete vaccination with two doses in the most fragile people, struck more heavily by the disease,” Van Laethem said.