In the late 60s there were 37 American vaccine manufacturers. Today the number is getting perilously close to zero. What happened?
This OC Register editorial provides some answers:
Litigation: So many pharmaceutical companies had been sued because of adverse side effects that many simply dropped out of the vaccine business, which is a low-profit sector to begin with.
Regulation: [I]n the 1980s, a company came up with a formula for a Hepatitis B vaccine genetically engineered by recombinant DNA techniques. Although safety was a secondary issue because no live viruses were involved, the FDA still forced the longest possible approval procedure, costing tens of millions of dollars and requiring years to complete ... Because flu viruses mutate, a new flu vaccine must be formulated every year. That means a new FDA approval every year, which adds to the cost.
Price Controls: [T]he Vaccines for Children program, set up in 1994, consisted of making the government the purchaser of 60 percent of vaccine for children - at deeply discounted prices. This made vaccine manufacturing even less profitable - or money-losing for some companies - and more companies simply got out of the business.