In 2004, the US Centers for Disease Control and Prevention signed an agreement with the Chinese National Influenza Centre to help China improve its analysis of seasonal flu strains.
Over the next 10 years, the fight against the disease was transformed. The US trained nearly 2,500 Chinese scientists and helped open dozens of laboratories in the country, a collaboration that proved instrumental in pushing the efficacy of the seasonal flu vaccine up from 10 per cent to over 50 per cent.
Now scientists are worried this type of collaboration is under threat, imperilled by mutual suspicions between the two governments, which have been exacerbated by the recent row over whether Covid-19 could have come from a lab leak in Wuhan.