The Centers for Disease Control has applied for and been assigned patents for a number of vaccines. Vaccines are a great tool for controlling disease.
The CDC licenses out their patents. I cannot find any actual discussion of licensing fees, but the form that you have to fill out to get a license asks for a market analysis. Presumably, so this is so they know how much they can charge you.
They are not making billions from this. Their entire budget is around 7 billion page 13. This line item break down of the CDC budget lists one budget item in the billions, Vaccines for Children. This is a taxpayer funded program that provides vaccines to "children who might not otherwise be vaccinated because of inability to pay."
In 2016 the CDC made 137.8 million from royalty income. Their total royalty income is slightly less than 2% of their budget. Presumably some fraction of that comes from its patents on vaccines.
Summary: The CDC makes a small percentage of its budget from licensing vaccine patents that it owns.