Because people will have had no prior exposure to a pandemic strain of influenza, everyone will need two doses: a primer and then a booster about four weeks later.

• 由于引发全球流感的病毒株是人类从未接触过的品系，因此每个人都需要注射两剂：第一剂为引子，四周后再追加第二剂强化疫苗。