THE vaccine is being administered at pace and scale to people who are able to isolate except for contact with their carers. Does this make sense while delivery is a scarce and critical resource? Much the same effect as vaccinating the cared-for and their carers could be achieved by vaccinating just the carers.

Age-based prioritisation reflects the higher risk of death if infected. But it does not take into account the lower likelihood of becoming infected for those who do not have to go out to work either to provide essential services or to support their families. Nor does it allow (as is usual in decisions on medical resource allocation) for the shorter period of healthy life which would be lost. It also neglects the smaller contribution to herd immunity from immunising the less interactive.

If such allocation is now appropriate, can we assume that all those whose encounters with the infected are not random, but deliberate and a matter of duty, have already been vaccinated? Can we expect that in a few days the NHS losing staff who need to isolate will be a thing of the past?

This matters when demand for NHS care may be about to exceed capacity. Furthermore, if this happens we will surely wish at least some rudimentary care for the overflow of patients triaged away from our hospitals. We could not in conscience allow this to be provided by volunteers who are unprotected. We need to be vaccinating a reserve of potential auxiliary nurses now.

It was perhaps not envisaged that the vaccine would become available at such a critical moment. This may be why the priorities appear to be driven by sentimentality rather than any serious operational analysis.

John Riseley, Harrogate.