What word is an adjective meaning "not first"?

In the following sentences, what single word can I use to summarize the ordinal numbers second, third, fourth, etc.?

When you take your second, third, fourth, etc. flu shot, call me.

If you have your second, third, fourth, etc. dessert, you might get a stomach ache.

When you have your second, third, fourth, etc. child, avail of this family planning class.

I've looked at this related question but the words subsequent, later, other, and contender do not seem to fit this context.

In particular, taking the first example, using "subsequent" changes the object to plural.

When you take your subsequent flu shots, call me.

I'm looking for a word that keeps it in singular form as I am not referring to the whole set of flu shots after the first one, but rather to the specific second, or third, or fourth, etc. instance of that flu shot.