Flu Shots: How Well Did They Work This Year?

Influenza vaccines for the 2024-2025 season showed promising results in preventing flu-related illnesses and hospital visits. Kids and teens saw a 32% to 60% reduction in outpatient flu cases and a 63% to 78% reduction in flu-related hospitalizations. Adults weren't far behind, with outpatient flu cases dropping by 36% to 54% and hospitalizations by 41% to 55%. This is great news, especially considering the increased spread of influenza A(H3N2) viruses, which usually make vaccines less effective. Despite the challenges posed by the A(H3N2) strain, this year's vaccine effectiveness was similar to previous seasons. This includes the 2023-24 season and even some seasons with higher effectiveness over the past 15 years. It's also worth noting that these findings align with interim reports from Canada and South America for the same period. However, there are some regional differences to consider. In the U. S. , most influenza A samples were A(H3N2), making up 67% of cases, compared to 48% in other networks. This variation could affect how well the vaccine works in different areas. One big takeaway is that getting vaccinated can significantly cut down on flu-related illnesses, doctor visits, hospital stays, and even deaths. With high levels of flu activity this season, encouraging more people to get vaccinated could make a real difference. But there are some limitations to these findings. The estimates are preliminary and could change as the flu season progresses. Vaccination status might also be misreported, especially in nontraditional settings like workplaces. Additionally, some kids might not have received the full recommended doses, which could lower the vaccine's effectiveness. There's also the possibility of other factors influencing the results, like previous vaccinations or underlying health conditions. Despite these challenges, the overall message is clear: getting vaccinated is the best way to protect against the flu and its complications. The data supports the recommendation that everyone aged 6 months and older should get the flu vaccine. For those who haven't gotten vaccinated yet, it's still a good idea to do so as long as the flu is circulating in their area.