Absolutely. Work should definitely proceed in parallel. The marginal utility of an extra dollar to a more or less fully funded research activity is small, even

Absolutely. Work should definitely proceed in parallel. The marginal utility of an extra dollar to a more or less fully funded research activity is small, even after factoring in the effect size. That same dollar spent on another disease could have much more benefit. Even without considering the varied research interests of scientists, or without considering any other human factors in the labor supply, the maximum benefit to humanity is not going to be achieved by throwing all or most money at a single disease.