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.