How effective is the seasonal flu shot and H1N1 vaccine?

Dr. Michael Roizen, MD
Internal Medicine
Flu shots are about 70 percent effective at preventing the flu in populations under sixty-five years of age, and somewhat less effective in people over sixty-five. The shots also reduce the severity of the symptoms in people who actually do get the flu. One study found that taking vitamin E and exercising, which boost the immune system, also seemed to improve the overall effectiveness of the vaccine.
The seasonal flu vaccine protects against three flu influenza viruses, including H1N1. There is not a separate vaccine for H1N1. The effectiveness of flu vaccine varies from season to season. How well the vaccine works depends on the age and health of the person who receives it and how closely it matches the virus the person is exposed to. Some seasons the vaccine is very effective, and some years it does not protect well against the flu. The best way to lower the risk of getting and spreading H1N1 or any strain of flu is getting a seasonal flu shot.
Dr. David L. Katz, MD, MPH
Preventive Medicine
There is some legitimate doubt about the effectiveness of the flu vaccine. It is certainly far from perfect, and the elderly, who most need protection, may need two inoculations to get it. Leaving aside some of the subtleties that complicate measuring vaccine effectiveness in real-world settings, and applying even a low-level estimate of overall vaccine effectiveness, routine flu vaccination produces a decisive overall benefit compared to just taking our chances with the flu.

Continue Learning about H1N1 (Swine Flu)

How can I protect my children from swine flu?
Dr. Jeanne Morrison, PhDDr. Jeanne Morrison, PhD
Protecting your children is very important. The best way to protect your child against swine flu (H1...
More Answers
How long am I contagious if I have swine flu?
Dr. Jeanne Morrison, PhDDr. Jeanne Morrison, PhD
If you have swine flu (H1N1), you are contagious from about a day before your symptoms begin until y...
More Answers
Are children at increased risk for swine flu?
Diana MeeksDiana Meeks
In general, influenza, including swine flu (H1N1) affects children differently than adults. In child...
More Answers
Can I get a seasonal flu shot and an H1N1 vaccine at the same time?
Diana K. Blythe, MDDiana K. Blythe, MD
You should get the seasonal flu shot at the same time as the H1N1 vaccine. In fact, after the 2009/2...
More Answers

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.