The World Health Organization (WHO) recommends the influenza strains to be included in each hemisphere's annual flu vaccination. Sometimes the formulations are the same for the Northern Hemisphere, which is currently entering flu season, and the Southern Hemisphere - where flu season occurs around April through October. They choose the virus strains most likely to cause widespread disease in the hemisphere's upcoming flu season, based on data collected in the months prior. Today, the WHO recommended that the vaccine be altered slightly from that produced for the Northern Hemisphere. (One component was recommended to be switched out.)
WHO did caution, "The amount of genetic and antigenic data available from recently circulating viruses has been significantly lower for this southern hemisphere vaccine recommendation meeting than is typical due to the COVID-19 pandemic." There have also been fewer influenza cases reported overall since the pandemic began. This is partly because travel restrictions and social distancing measures help prevent influenza as well as COVID-19. And it is also because influenza surveillance was disrupted during the early stages of the pandemic, with far fewer specimens tested for flu than usual. WHO says, "It is unknown what impact the low level of influenza activity will have on forthcoming influenza seasons and which influenza virus types and subtypes will begin to circulate widely when social interactions resume."