The vaccine manufacturers set unrealistically high targets and now they are struggling to fulfill them. And this has happened to almost all the manufacturers, including Pfizer, Moderna and the Gamaleya Research Institute. According to the latest stats, some 63 million people have received at least one shot of the vaccine till now, including 21.1 million in the US (the original target was 20 million in the US by December end).
That is not easy to all manufacturers to supply every country that affected of virus , so manufacturers need to divide it to equal and then supply the countries that need much of this. And about the latest in US there is not end i think the case still going up and US need much there target even here in my country suffered in the vaccine crisis also economic affect this happening so if a human we need to obey all the good procedure of our country for our own safe.