> two exclusive contracts?

The EU signed second and, to my knowledge, did not include similar language in their agreement. They are also paying less than the UK and US.

According to AZ they are selling the vaccine at cost to all customers, so the price should have nothing to do with it. Unless they're lying I guess.

I think profits will come from page 5, paragraph a (the second a on that page):

"(a) costs related to the operation of the facility incurred while using the facility to manufacture other products;"

are included in the vaccine costs.

Including similar language in their agreement would probably have made the EU's already terrible case even worse anyway, since it would almost certainly have only covered AstraZeneca's non-UK European facilities, and the whole problem seems to be that those can't produce nearly enough vaccine to cover EU demand. Note that the current clause about the initial supply of doses only covers manufacturing them within the EU; the part about the EU including the UK explicitly does not apply to that clause. (Indeed, the only mention of UK manufacturing seems to be exempting it from a clause banning the use of non-EU manufacturing sites.)

Op meant having the same clause for the Pfizer/BionTech vaccine, which was developed and is mostly produced in the EU.

If the EU had done that, things would look quite different today. Even for the UK.

We can all be glad that the EU was quite a bit more naive than the UK.

Somehow I doubt the UK would have been so happy to rely on in-EU production of the Pfizer/BionTech vaccine if they'd done that. As I understand it, the UK production facilities for the AZ vaccine exist mostly because the government wanted at least one UK-produced vaccine in case Trump pulled some kind of vaccine nationalism move and restricted exports. If there was reason to suspect the EU was the one likely to do that...