The Whitehouse apparently said on live TV press briefings that no vaccine has left US shores since Biden took over.
https://www.globaltimes.cn/page/202103/1218325.shtml
Something like 30 million AstraZeneca vaccine sits in the US being unused, and it is not clear if or when it will be approved in the US.
The US has produced the most vaccine, and it is understandable that they would want to vaccinate their own population first.
For countries with no contracts or advance payment, it is reasonable for them to wait for other countries to start to sell their excess vaccine.
However - the US will soon have double the amount they need...
Advance payment contracts were agreed upon by the EU, UK and a few others with American vaccine manufacturers. This was back in May last year.
If Europe ends up taking the Russian vaccine with AstraZeneca - by the time they get the vaccine from the US, it will be useless.
If a country has a plan that a supplier will meet their commitments, and this does not happen because the US government has blocked vaccines leaving- it defeats the purpose of having a contract or making advance payment.
It certainly raises questions of not having a plan B- but billions have been paid in advance as well.
The UK has just received a big shipment from India, the manufacturing centre that plans to have billions of dosages. Vaccines may increase to over 5 million people per week in the UK.
Perhaps the agreement should have been to publish the vaccine recipes so that all countries could create generics. (And then compensate the vaccine companies for their efforts).
This would have sped up the production of vaccine manufacturing with more sites around the world.