Getting an influenza (flu) shot is usually pretty routine, but as of 2003 you have a couple of new things to consider.
Because of shortages in 2001 and 2002, the CDC's Advisory Committee on Immunization Practices had recommended early this year that providers reserve October vaccinations for people over 50, health care workers, and others at increased risk for flu complications. Everyone else was asked to wait until November. However, vaccine production was on target for the 2003-2004 flu season - some 90 million doses of vaccine will be available - so everyone can start receiving shots in October.
Like other vaccines, the flu vaccine exposes the body to just enough of the influenza virus or its antigens so the immune system sets up a defense against it. A small percentage of people get mild flu-like symptoms a few hours after receiving the shot, but the most common reaction is redness, soreness, or swelling at the injection site. The virus types that cause the flu (A, B, and the less common C) can mutate to produce different strains, so if you want to be protected, you must be re-vaccinated every year.
Another change may be welcome to people who don't like injections. In June 2003, the FDA approved FluMist, the first influenza vaccine delivered by a nasal spray. This vaccine uses a live but weakened virus, unlike the flu shot, which is made with a killed one. The weakened virus can grow in the nasal passages but not in the warmer conditions found in the lungs, where influenza develops. In one trial of adults ages 18-41, FluMist protected 85% of those exposed to a strain of the virus. Injected flu vaccines are 70%-90% effective.
Because clinical trials focused on children and younger adults, the nasal spray was approved only for those ages 5-49. For children ages 5-8, the first exposure to FluMist requires two doses, six weeks apart. Patients ages 9-49 need only one dose. FluMist was not approved for patients under 5 because in clinical trials young children treated with the nasal mist had a higher rate of asthma attacks and wheezing within 42 days of the vaccination, compared to children who received a placebo.
Pregnant women, people over 50, and people with chronic illnesses, including asthma, should not be given FluMist; its safety and efficacy in these groups is not known. And if you have a medical condition that predisposes you to severe flu infections or are over 50, you should receive an injected vaccine rather than FluMist. The same goes for people with weakened immune systems.
Remember that the injectable form of the flu vaccine is not for everyone either. For instance, if you suffer from severe egg allergies, have ever had a severe reaction to a flu shot, or have developed Guillain-Barre syndrome (which causes temporary loss of movement and sensation within a few weeks of getting a flu shot or having a viral illness), talk to your doctor before getting a flu shot or taking FluMist. Many people mistakenly underestimate the risks associated with influenza. It's far worse than a bad cold. About 114,000 people are hospitalized and 36,000 people die annually from the flu, most of them over 65. Almost as many people die from leukemia and ovarian cancer combined. No vaccine guarantees complete protection, but if you get the flu vaccine and still get the flu, chances are you won't become as ill.
October 2003 Update