Tuesday, September 30, 2014

Should Seniors get a High-Dose Flu Shot?

Have you gotten your annual flu shot yet?
Yesterday I went to get my flu shot. I was surprised when I was asked whether I wanted a “High-Dose” shot. This was something new to me, and I didn’t know how to respond. Since I expect that other seniors are also unfamiliar with high-dose shots, I thought I would post this brief article on the subject.
Warning: I am a lawyer, not a medical professional. I hope readers with more medical training will feel free to comment on this subject or email me with additional information.    
To find out more, I went to the website of the Centers for Disease Control and Prevention (CDC), the government’s health protection agency, to see what it says about whether seniors should be getting the high-dose shot.
Here is what the CDC says: “Fluzone High-Dose vaccine contains four times the amount of antigen (the part of the vaccine that prompts the body to make antibody) contained in regular flu shots. The additional antigen is intended to create a stronger immune response (more antibody) in the person getting the vaccine.”
The CDC then goes on to try to answer some of the questions older adults may have.
Why is a higher dose vaccine available for adults 65 and older?
Human immune defenses become weaker with age, which places older people at greater risk of severe illness from influenza. Also, ageing decreases the body's ability to have a good immune response after getting influenza vaccine. A higher dose of antigen in the vaccine is supposed to give older people a better immune response, and therefore, better protection against flu.
Does the higher dose vaccine produce a better immune response in adults 65 years and older?
Data from clinical trials comparing Fluzone to Fluzone High-Dose among persons aged 65 years or older indicate that a stronger immune response (i.e., higher antibody levels) occurs after vaccination with Fluzone High-Dose. Whether or not the improved immune response leads to greater protection has been the topic on ongoing research. A study published in the New England Journal of Medicine indicated that the high-dose vaccine was 24.2% more effective in preventing flu in adults 65 years of age and older relative to a standard-dose vaccine. The confidence interval for this result was 9.7% to 36.5%).
Is Fluzone High-Dose safe?
The safety profile of Fluzone High-Dose vaccine is similar to that of regular flu vaccines, although some adverse events (which are also reported after regular flu vaccines) were reported more frequently after vaccination with Fluzone High-Dose. The most common adverse events experienced during clinical studies were mild and temporary, and included pain, redness and swelling at the injection site, headache, muscle aches, fever and malaise. Most people had minimal or no adverse events after receiving the Fluzone High-Dose vaccine.
Who can get this vaccine?
Fluzone High-Dose is approved for use in people 65 years of age and older. As with all flu vaccines, Fluzone High-Dose is not recommended for people who have had a severe reaction to the flu vaccine in the past.
Does CDC recommend one vaccine above another for people 65 and older?
The CDC and its Advisory Committee on Immunization Practices have not expressed a preference for any flu vaccine indicated for people 65 and older. CDC recommends flu vaccination as the first and most important step in protecting against the flu.
Based on this information, I personally decided to get the high dose shot. It's covered by Medicare. 

I hope the information above helps you be better informed when you get your flu shot this year.
Further Reading:
Fluzone High-Dose Seasonal Influenza Vaccine, Questions and Answers, Centers for Disease Control and Prevention (page last reviewed and updated: September 3, 2014).

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