The flu shot provided “substantial protection” for all age groups, including elderly and immunocompromised populations, during this influenza season, the Center for Disease Control reported Wednesday.

The Advisory Committee on Immunization Practices presented new findings that showed people who received the influenza vaccination were well protected from “inpatient, emergency department, and outpatient illness among all ages” in the 2022-2023 season. 

It also reduced the chance of hospitalization from Influenza A — the virus that causes flu pandemics — in children by nearly three-quarters, and in adults by nearly half, the CDC said in a press release.

“These data underscore that flu vaccination can offer substantial benefit against flu and its potentially serious complications,” the agency said.

One of the referenced studies in the presentation determined that the influenza vaccine was 45% effective among children against the predominant virus. In comparison, during previous seasons, this rate has been about 30%, the CDC wrote.

Additionally, vaccinated children were 68% less likely to be hospitalized, and 48% less likely to visit an emergency department due to a flu or flu-related sickness, the CDC found.

In a similar trend, adults overall were 44% less likely to visit an emergency department and 39% less likely to be hospitalized for a flu-related illness or complication. In comparison, adults were just 25% less likely to be hospitalized or visit emergency departments and urgent cares during the 2021-2022 season with the last vaccine.

Researchers emphasized the effectiveness of the vaccine among people above 65 years of age and the immunocompromised population, two groups that are more likely to get a more severe illness from the flu and less likely to have an immune response to the vaccine. 

The 2022-2023 flu virus peaked in November and early December, when the percent of positive tests hit about 26%. The percent of positive cases is now at approximately 1.7%. Influenza-related hospitalizations have also leveled.

While the number of flu patients has gone down, the CDC noted that this season’s influenza activity was higher and more damaging than it was in the previous two seasons. In fact, there were 111 influenza-associated deaths among children.