The 1 dose vs 2 doses covid vaccine saga is a real ethical dilemma for clinicians involved in the delivery of vaccinations. There'll be medical ethicists out there who can pull together a more cogent discussion than me but here's my 2p worth. (1)

Deontological approach: Most clinicians want to do their very best for their individual patients. And many will see it as a their moral duty to do so. As individual patients that's what we want too. Giving 2 doses is the "right" thing to do. (2)

This approach has an absolutist lens as well between Right vs Wrong. So our natural tendency will be to follow the vaccine trial protocols, medical licensing, manufacturers instructions etc... There's a "certainty" to this. (3)

The counter approach is the utilitarian view of the greatest good for the greatest number. A single dose would save more lives. Where resources are limited there will be this trade off. Giving some patients 2 doses means denying others the protection of 1 dose. (4)

The utilitarian approach tends to align with the population health approach, as the perspective is of the welfare of groups of people rather than individuals. Unsurprisingly this will conflict with the patient-centric values that most clinicians will have. (5)