I'm sorry to say that I snickered a little bit at your question, ... and that's just because the only obligation that capitalist companies, like the big drug companies, care about is making money. If they care about humanitarianism in any way, it is more of an image issue.
Take it from the wife of on organic chemist. My husband used to work for one of those large pharmaceutical giants, and we will both attest that they cared most about their bottom line. Kudos to brettd, though. I like the distinction between "legal obligation" and "moral obligation."
I think that the individual chemists (and other workers) feel more of that moral obligation than the company does. Ironically, sometimes those same workers are penalized for that very moral obligation. Therefore, if you had worded your question differently by referring to "the people who create new vaccines and medicines," this thread could contain VERY different responses!