Yes it is. Both subjects are sick. Both subjects are ill. Both cases have a cure or treatment. The knowledge and means for both treatments exist. Both SHOULD be treated.

Now..! How does society organize itself to use resources that do exist to meet needs that also exist? Is private individual inurance the adequate form of organization in healcare? What is the ethical way for a society to care for its ill and sick?

Now... Why does A pay for insurance? To be treeated? Or to make sure he holds exclusivity in the treatment? In other words, why does A have to do with B's illness? What do You call people who live looking at what their neighbours have and have not?

Now... Is treatment a status thing? Should it be? Is it ethical for A to want to have exclusive access to treatment? If A demands that B does not receive healthcare because he hasn't paid for insurance, would that be ethical?

And especially... is it ethical that insurance companies preclude that society cares for its ill and sick because they are ill and sick? Is it ethical that B's treatment should be denied with the sole objective to force the purchase of a private and exclusive service?

«This is my truth, tell me yours.»
Aneurin Bevan