Another more fundamental criticism challenges whether vaccines should have been procured at all given an eventual surplus in the developed North. The unexpected finding that a single dose was immunogenic among all persons except for younger children, which reduced the required number of doses by half from the projected number needed in most countries, but this was not known in advance of countries placing vaccine orders. Had there been ''overpreparation''? The prior worry had been the reverse -would there be sufficient production capacity to meet needs [38] ? Even in retrospect, and with the observed burden of the pandemic, a vaccine was clearly justified for countries where annual vaccines for seasonal influenza are routinely recommended.