• Question: how do scientists know how to make a flu vaccine if viruses can be diffrent every year?

    Asked by camelialequeux to Kat, Andrew, Katie, Sadaf on 20 Jun 2013. This question was also asked by gmjagger.
    • Photo: Andrew Swale

      Andrew Swale answered on 20 Jun 2013:

      Scientists carry out research to discover which three influenza viruses are most likely to infect people in the upcoming ‘flu season’. They then produce a ‘trivalent’ vaccine which protects against these three.

      The viruses in the vaccine can change each year based on international surveillance and scientists’ estimations about which types and strains of viruses will circulate in a given year

Comments