I've thought about this a lot. Drug manufacturers have about a 5-7 year window to maximize profits on new and risky drugs before the number of adverse effects becomes too great and the drug is withdrawn from the market or is given a "black box warning". A warning of this type is meant to inform the consumer that there is a reasonable chance that harm will come to you if you take this, so use as a last resort.

Even though this is a "vaccine", and the manufacturers can't be sued if you fall ill or die from it, they will still have about 5 years to convince people to get it before the adverse effects reports become too great and people stop getting it. This revenue stream drying up simply won't do for big pharma, and creating a new plague won't work again. They have to create lifetime clients when they have the chance, right now, with this vaccine.

Edited to finish my post: infecting recipients with HIV that shows up years from now would certainly assure lifetime customers.