South Africa's Flu Shots Found 81% Effective

South Africa's latest Public Health Bulletin shows that influenza activity peaked during epidemiological week #22 (June 4, 2023) and had an overall detection rate of 12% (942) for the 2023 season.

The mean onset of the influenza season in South Africa from 2005-2019 was week #17 (3rd week of April).

As of December 1, 2023, Influenza infections this year were dominated by A(H3N2) (98%), with most influenza infections causing mild illness.

For the current flu season, vaccine effectiveness for any influenza in individuals of all ages was 81% [95% confidence interval (CI) 29%-95%)], and for A(H3N2) was 76% [95% CI 10%-94%].

The World Health Organization (WHO) recently announced its recommendations for the composition of the 2024 Southern Hemisphere influenza vaccines, including a change to the A(H3N2) vaccine component.

In addition, the WHO confirmed that including a B/Yamagata lineage antigen in quadrivalent influenza vaccines is no longer warranted for the next flu season.