Yes, clearly. With COVID-19, there is pretty much guaranteed market for about ten billion doses. Along with direct investment by governments in wealthier countries. Most people, including politicians, want a COVID-19 vaccine real bad.

The parent poster was describing the situation with vaccine development in general, to which COVID-19 is quite the exception. A potential hepatitis C vaccine for example has very different economics, as it would not be deployed anywhere nearly as widely or quickly. Consider that, 40 years after hepatitis B immunization became available, the majority of Americans haven't been jabbed with it.