(NYTIMES) Soon after the novel coronavirus emerged, its genome was sequenced and vaccines were developed at, yes, warp speed. These are all herculean tasks that deserve praise. But America's achievement stops there. The initial vaccine strategy was reactive and tactical, not decisive and strategic. While it prioritised getting safe, effective vaccines into bodies as quickly as possible, it did not consider how to prevent variants or subsequent waves of the virus.

All coronaviruses produce variants, and as with prior coronavirus outbreaks, variants of Sars-CoV-2 emerged as the virus spread from Wuhan, China, across the planet. The next danger is the further evolution of variants that can overcome the immunity provided by existing Covid-19 vaccines and prior infections.