It is a big day for science,

That is a big spike.

Vaccine production in this country is not tied to public health priorities.

We're depending on the American distribution system set out by private enterprise; that accounts for its complexity,

Only half goes directly from the manufacturers to the end users (such as pharmacies). The other half goes through a very complex distribution chain, from one company to another to another, two or three times, before it gets to the end user,

We should not expect perfection, or we'll be disappointed.