This season’s flu vaccine was a good match for the virus strains circulating in the U.S., according to a weekly report from the U.S. Centers for Disease Control and Prevention (CDC).
They estimate that the vaccine was 47% effective at preventing infections with the H1N1 influenza virus, which was the dominant strain in the U.S. between October 2018 and February 2019.
The CDC also found that nearly 90% of flu illnesses were H1N1, which is a milder variety of the flu. Only 10% of cases were H3N2, a stronger version of the flu that dominated last year’s flu season.
The last flu season was one of the worst in decades, with nearly 50 million illnesses and around 80,000 deaths.
Currently, the CDC estimates that between 9,600 to 15,900 people died of the flu between October 2018 and February 2019, and noted that this was “a low-severity influenza season.”
Furthermore, people who got flu shots this season were likely very well protected. Both the H1N1 and the H3N2 viruses circulating in the U.S. were closely matched to the vaccine strains.