#18,344
Although Florida is now less than 48 hours from the expected arrival of Hurricane Milton, one of my pre-evacuation preps yesterday was to get my seasonal flu shot. Two weeks ago, in preparation for our close encounter with Helene, I got my fall COVID vaccine.
Last year, I also updated my Tetanus shot (Tdap).
As I've explained previously (see #NatlPrep: Giving Your Preparedness Plan A Shot In The Arm), the last thing you want to have to deal with during an emergency is being sick. And when you are stressed, and fatigued - and maybe cooped up with a lot of other people - your chances of catching something go up.
Admittedly, Flu and COVID vaccines only provide modest protection against infection, but they usually do a better job at reducing severe illness and hospitalization. And since severe influenza infection is linked to strokes and heart attacks, even a modest amount protection can be lifesaving.
Yesterday the CDC's MMWR published the results of a study of this year's flu vaccine effectiveness (VE) in 5 South American countries (Argentina, Brazil, Chile, Paraguay, and Uruguay) - which has the same components as the Northern Hemisphere's fall vaccine - and reports that it reduced the risk of hospitalization in high-risk patients by 35%.
While far from a stellar result, it is a significant reduction of risk. One that I'm more than happy to have on board, given the challenges ahead.
I've only reproduced the Abstract and summary. Follow the link to read the report in its entirety. I
Weekly / October 3, 2024 / 73(39);861–868
Erica E. Zeno, PhD1,2,*; Francisco Nogareda, MPH3,*; Annette Regan, PhD3,4; Paula Couto, MD3; Marc Rondy, PhD3; Jorge Jara, MD3; Carla Voto, MD5; Maria Paz Rojas Mena, MD5; Nathalia Katz, MD6; Maria del Valle Juarez, MPH6; Estefanía Benedetti, MPH7; Francisco José de Paula Júnior, MD8; Walquiria Aparecida Ferreira da Almeida, PhD8; Carlos Edson Hott, MBA8; Paula Rodríguez Ferrari, MSN9; Natalia Vergara Mallegas, MPH9; Marcela Avendaño Vigueras9; Chavely Domínguez, MD10; Marta von Horoch, MD11; Cynthia Vazquez, Phd12; Eduardo Silvera13; Hector Chiparelli, MD14; Natalia Goni, PhD14; Laura Castro, DrPH1; Perrine Marcenac, PhD1; Rebecca J. Kondor, PhD1; Juliana Leite, PhD3; Martha Velandia, MD3; Eduardo Azziz-Baumgartner1; Ashley L. Fowlkes, ScD1; Daniel Salas, MD3; REVELAC-i Network
Summary
What is already known about this topic?
Influenza vaccine effectiveness (VE) varies by season.
What is added by this report?
In five South American countries (Argentina, Brazil, Chile, Paraguay, and Uruguay) the 2024 Southern Hemisphere seasonal influenza vaccine reduced the risk for influenza-associated hospitalization among high-risk groups by 35%. VE might be similar in the Northern Hemisphere if similar A(H3N2) viruses predominate during the 2024–25 influenza season.
What are the implications for public health practice?
CDC recommends that all eligible persons aged ≥6 months receive seasonal influenza vaccine. Early antiviral treatment can complement vaccination to protect against severe influenza-related morbidity.
Full Issue PDF
Abstract
To reduce influenza-associated morbidity and mortality, countries in South America recommend annual influenza vaccination for persons at high risk for severe influenza illness, including young children, persons with preexisting health conditions, and older adults. Interim estimates of influenza vaccine effectiveness (VE) from Southern Hemisphere countries can provide early information about the protective effects of vaccination and help guide Northern Hemisphere countries in advance of their season.
Using data from a multicountry network, investigators estimated interim VE against influenza-associated severe acute respiratory illness (SARI) hospitalization using a test-negative case-control design. During March 13–July 19, 2024, Argentina, Brazil, Chile, Paraguay, and Uruguay identified 11,751 influenza-associated SARI cases; on average, 21.3% of patients were vaccinated against influenza, and the adjusted VE against hospitalization was 34.5%. The adjusted VE against the predominating subtype A(H3N2) was 36.5% and against A(H1N1)pdm09 was 37.1%.
These interim VE estimates suggest that although the proportion of hospitalized patients who were vaccinated was modest, vaccination with the Southern Hemisphere influenza vaccine significantly lowered the risk for hospitalization. Northern Hemisphere countries should, therefore, anticipate the need for robust influenza vaccination campaigns and early antiviral treatment to achieve optimal protection against influenza-associated complications.
There is still time for Floridians in the path of Milton to get the flu/COVID vaccines, as well as those struggling to deal with the aftermath of Helene. I know it may seem pretty far down your list of things to do.
But during an extended disaster, you need every edge you can get.
