In the United States (and the rest of the Northern Hemisphere), flu season occurs in the fall and winter. While influenza viruses spread year-round, most of the time flu activity peaks between December and February, but activity can last as late as May. The overall health impact (e.g., infections, hospitalizations, and deaths) of flu varies from season to season. In the Southern Hemisphere, flu season typically occurs from June to September, but this year it started early—in April-- and has already peaked months ahead of its typical pattern. As such, we expect flu season to come a bit early this year and it is recommended that people get their flu shots by the end of October. The flu vaccine is quadrivalent meaning it protects against the four most common strains of influenza virus that circulate globally each year. It takes 2 weeks to develop protection after vaccination. Influenza viruses mutate quickly due to their genetics. Annual vaccines confer optimal protection for ~6 months, so the goal is to be protected throughout the flu season (and getting your shot now through the end of October is the right timing for this year). The flu vaccine is recommended for everyone over the age of 6 months. We have lots of content planned on influenza and flu vaccines (including addressing misconceptions about flu vaccine efficacy), so stay tuned! But, in the meantime, schedule your flu shots (and remember, they're safe to get at the same time as your COVID-19 booster if you want to knock them out at the same time). If you've ever had the flu, you know that it can be miserable-- and the flu vaccine can help protect you from the flu and significantly minimize those crummy flu symptoms and shorten the duration of illness.