After having beaten established vaccine makers to produce the first Covid-19 shots, Moderna and BioNTech, with its partner Pfizer, are racing to dethrone them in another big market: flu.
They are betting that the new messenger RNA technology used in their Covid vaccines at large-scale for the first time, will eventually allow flu jabs to be developed more quickly to match ever-changing annual strains and improve efficacy rates of between 40 and 70 per cent.
The challengers have also forced incumbents such as Sanofi, Seqirus and GlaxoSmithKline, to speed up their research into mRNA alternatives, even though they argue their existing products may still prove superior.