Last three pras of the article:
"The first part of the vaccine roll-out has been a triumph, but that should not put it beyond constructive criticism. The delay to the second dose was an audacious and successful calculated gamble led by the Joint Committee on Vaccination and Immunisation. But it was there initially to solve the problem of limited supply and a raging second wave. There can be no doubt that it saved lives.
Now, though, we have a different problem: we need to administer as many second doses as possible, as soon as possible. As the easing of restrictions looms, it is difficult to see why we are not just ramping through the second doses, bringing vaccination schedules forward and ensuring those that have already had a single dose are better protected in the short to medium term.
Instead we are stuck with a rigid enforcement of a slightly arbitrary 8-12 week schedule, which risks undercutting the current need to get as many people fully dosed as possible. It would be a shame to see younger people scapegoated (as they have consistently been at various points during the pandemic), when there are plenty of people mostly in their twenties and thirties who are keen to get second doses which they are currently prevented from having."
Not sure I would equate "calculated gamble" with arbitrary. Subtle difference.