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.