by Steven D. Blatt, MD
“It’s no big deal.”
“Everybody gets the flu.”
“The flu shot will make me sick.”
“I got it once. Why do I need it again?”
These are just a few of the responses that people say when offered a flu vaccine. What are the facts and how does one decide if they should get the vaccine?
First, what is the “flu?” Patients often use “flu” interchangeably with “viral infection.” For example, someone will say, “I was home sick for three days with a stomach flu.” That is not the type of flu we are discussing. Flu vaccine protects against Influenza. There are many different varieties of Influenza and ways of categorizing them. There are Influenza A and Influenza B. Influenza A has different subtypes based on two proteins “H” and “N.” For example, the strain that caused “swine flu” in 2009 was a strain of H1N1.
The flu vaccine comes in two forms, the “shot” and the nasal spray or “mist.” The shot is an inactivated or killed vaccine. During the manufacturing process, the virus is killed and purified. It is impossible to get Influenza from the shot. This formulation is approved for anyone older than 6 months of age. The nasal spray vaccine is made from a live virus that is weakened. This vaccine is only approved for healthy people, aged 2-49 who are not pregnant. Individuals with respiratory illnesses, such as asthma, or who have diabetes should not receive this vaccine. Since flu vaccine manufacturing process involves chicken eggs, those with a severe allergy to eggs should not be vaccinated. If your child has an egg allergy, tell your doctor before receiving the vaccine. Both vaccines are safe and both work well. Surprisingly, the one without the needle, the nasal spray, works a little bit better.
Each year, scientists review surveillance data to predict which influenza strains are likely for the coming year. This information is used to determine the components of that year’s flu vaccine. For 2011-2012, the strains in the vaccines are an H1N1 virus that emerged in 2009, an H3N2 virus, and a B virus. This year’s vaccine is made specifically for this flu season. Manufacturers try to make just enough for the year. Unused vaccine will be discarded at the end of the year. Flu vaccines are available from your physician, flu clinics, and more recently, pharmacies. They become available in September, but early on, the supply may be variable. For those that delay, there is still value in getting the vaccine as long as flu is in the community. There was still significant flu activity in New York State in April 2011. Getting the flu vaccine in February still provided protection.
When you’re done reading this, please schedule your flu vaccine, for you and your children. We don’t know when flu season will begin, so the earlier the better. The more people in your family who are immunized, the less likely you can spread the flu to someone else. Remember, the primary way to prevent the spread of any infection, including the flu, is with good hand washing, covering one’s mouth and nose when coughing and sneezing, and staying home from daycare, school or work for 24 hours after a fever is gone. An excellent website to learn more about the flu is from the Centers for Disease Control and Prevention or CDC website at http://www.cdc.gov/flu/