A recent CDC study published on October 3 revealed that this year's flu vaccine reduced hospitalization risk by 35% in the Southern Hemisphere, with even higher effectiveness observed among vulnerable populations.

Specifically, the vaccine was found to reduce hospitalization risk by 59% for individuals with chronic illnesses, 39% for young children, and 31% for older adults.

During the 2023/24 flu season, influenza A was the dominant strain, while influenza B was rarely detected.

In the U.S., flu hospitalizations during the 2023-2024 season ranged from 380,000 to 900,000, with vaccination efforts preventing an estimated 105,000 to 240,000 hospitalizations.

Despite these efforts, flu shot uptake in the Southern Hemisphere remained low, with only 21.3% of the population vaccinated.

These findings underscore the need to optimize vaccination policies and highlight the importance of continuous monitoring of influenza strains to improve vaccine effectiveness.

Experts suggest that if similar flu strains circulate in the Northern Hemisphere, comparable protection levels may be expected from the upcoming 2024-25 vaccine.

Historically, vaccine efficacy against the A(H3N2) strain ranges from 24% to 43%, which aligns with the current vaccine's risk reduction.

Over 11,700 high-risk individuals were hospitalized with severe respiratory illnesses, with approximately 3,850 testing positive for the flu, primarily for the influenza A virus.

The CDC recommends that everyone aged six months and older receive the influenza vaccination annually, ideally before the end of October.

Vaccination is emphasized as one of the most effective ways to prevent complications from influenza, which can lead to severe outcomes and fatalities.

Severe flu cases can result in up to 71,700 deaths annually across the Americas, highlighting the critical need for vaccination.