There are outbreaks of preventable diseases left and right. Preventable, not very treatable. And once it breaks out, it mutates, so the prevention stops working.
And that's why they needed as many people as possible to be vaccinated, because the problem could only escalate if it got out. Well, it got out. And the pharmaceutical companies are gonna make SO MUCH MONEY. Vaccines were selling well. But this is creating a whole new need. Like the twist in the "Promised Land" movie with Matt Damon.