What’s the reason for the zero article after a preposition and countable noun in “a change of X” and in “a switch from X to Y”?

I am a non-native speaker of English and therefore need your help. The question is: why do we use the zero article in the phrases “a change of X” and “a switch from X to Y”?

For instance:

• a change of address




• a change of government




• a switch from student to teacher

The words following the prepositions set in bold (that is, address, teacher, student, and government) are all countable nouns, are not they?

So why do they get to be used without an article given that they are countable nouns?

How are they different from a change and a switch, which do have an article before them?