CDC Expert Answers Our Questions About the Flu and Flu Vaccine

Health Professional

Our expert, Kathi MacNaughton, RN, interviews Dr. Carolyn Bridges of the Centers for Disease Control And Prevention about the flu, asthma and the flu shot and why everyone can't get FluMist, the flu vaccine that doesn't require a needle.

Have a question or comment? Click here.

Are there things you want to know about the flu and the flu vaccine? If so, you're going to love this article.

I recently had the opportunity to speak one on one with Dr. Carolyn Bridges, the Associate Director for Science in the Influenza Division of the Centers for Disease Control (CDC). This CDC unit is responsible for a number of tasks, including:

  • Year-round influenza surveillance throughout the world
  • Coordinating with state and local health departments
  • Global decision-making with the World Health Organization (WHO) on flu vaccine content twice a year
  • Influenza risk assessments
  • Studies of the flu disease burden
  • Antiviral resistance research and monitoring
  • Improving community and public awareness of the flu and flu prevention

As you can see, the Influenza Division has their hands full. They also maintain a comprehensive mini site about the flu and flu vaccine: http://www.cdc.gov/flu/protect/keyfacts.htm

You'll find answers to most of your basic questions and concerns there. So, I thought I'd go "a step beyond" and ask Dr. Bridges questions you won't necessarily find on most websites about the flu. Here are my notes from the interview:

Q: How effective is this year's flu vaccine expected to be, in light of last year's less than stellar results?

A: The 2008-2009 flu protection is expected to be much better than last year's. Unfortunately, decisions have to be made on a very tight timeline about what strains of flu virus to include in the vaccine a year in advance of peak flu season, in order to allow time for vaccine manufacturers to make the vaccine. At best, experts have to make educated guesses about what strains of flu virus will be circulating in the coming year. Since a hallmark of flu viruses is their ability to change quickly, it's not an easy task. New strains crop up all the time.

The good news is that the CDC/WHO have been very accurate overall in predicting which flu virus strains to include in the yearly vaccine. 16 out of the last 20 years, the match between prediction and reality has been good. Only once in that time was the prediction totally off, in the 1997-98 flu season. Also good news is that even if the exact strains circulating are not in the vaccine, people who are immunized generally have a fair amount of cross-reactive protection. That means that you'll still be at least partially protected against other circulating viruses, even if not specifically vaccinated against them.

It's important to note too that although the CDC, along with the WHO, makes recommendations about flu vaccine twice a year (once for the northern hemisphere and once for the southern), which are published as updates by the Advisory Committee on Immunization Practices (ACIP), it is ultimately the US Food and Drug Administration (FDA) who makes the final decisions on what goes into the flu vaccine.

Q: For people with asthma who don't like shots, is it acceptable to just wait & see if the flu comes and then take one of the antiviral drugs to treat it?

a: There are a number of reasons why this strategy doesn't make sense. First of all, the best way to ensure asthma control and respiratory health during flu season is for people with asthma to get a flu shot. Nothing else is as effective at preventing the flu as the flu vaccine.

And FluMist, the nasal spray vaccine, is not an option either for people with asthma. I asked why, and Dr. Bridges told me that there simply is not enough data yet to take a risk with people over age 49, people with chronic illnesses, pregnant women or kids under the age of 2 years. It is probably safe, but some European studies showed some risk of side effects, including Bells Palsy. Until they have more data, we'll need to stick with the flu shot.

Now, about the antiviral flu drugs, such as Tamiflu and Relenza, for treating the flu once you come down with it. When used as prescribed, these drugs are about 70 to 90% effective. They'll also reduce the severity of your flu symptoms and shorten the time you are sick by 1 or 2 days. In addition, they may make you less contagious to other people.

Keep in mind though, that before you realize you have flu symptoms and begin treatment, you are highly contagious and you may transmit the flu to friends, families and co-workers. Also, the antiviral drugs must be started within 2 days of the first flu symptom and then must be taken twice every day for 5 days. Getting treatment started so soon and then sticking with it is hard for a lot of people, which reduces the effectiveness of the treatment.

(So, Dr. Bridges emphasizes that the flu vaccine is the absolute BEST method for preventing the flu and staying healthy!)

Q: Kids under the age of 6 months can't be immunized against the flu currently. What options do we have for keeping them healthy this flu season?

A: The reason why young infants aren't recommended to be vaccinated against the flu is because studies have shown that their antibody response to the killed flu virus isn't great. But, these young babies are also at high risk for serious flu-related complications. So, their protection against the flu must come from those in their environment. Here are some suggestions that should help:

  • All family members and infant caregivers should be immunized against the flu. If no one around the infant can get the flu easily, then the infant's chances of staying healthy are much greater.
  • In addition, use good handwashing techniques all during flu season when caring for an infant. Wash your hands thoroughly with warm water and soap before handling the infant.
  • Pregnant women should be immunized against the flu, as there is evidence that this provides passive protection to the infant for up to 6 months after birth, particularly if the mother breastfeeds.
  • Be observant of your infant. Observe him/her closely for symptoms of respiratory illness. If your child develops a fever (100°F or higher under the arm, 101°F orally, or 102°F rectally), respiratory symptoms, or is less responsive than normal, contact your child's doctor.

What is the best way to get the "prevent the flu" message to all high risk groups?

As I stated earlier, Dr. Bridges pointed me to a number of detailed and easy to read pages on the CDC website that can help you learn more about the flu and flu vaccine options. Here are a few I think you might find of interest:

Visit our Cold & Flu site for more information about preventing and managing the cold and flu.