If you agree with the point on research scientist vs. process engineer I made above, what would open-sourcing it bring? And Bill Gates explains why it might be counterproductive: you need to screw up only once and in a relatively minor way to completely break public trust in this kind of a product. We shall recognise that vaccines are not software. It sounds reasonable to me. And in the end, we’ll never know what could have been, just what really happened.