Seasonal influenza describes strains of the flu that are responsible for "flu season". One way of preventing seasonal influenza is to get vaccinated against the viral strains causing the infections. One form of seasonal influenza vaccine, called FluMist, comes as a nasal spray and is effective at producing immunity against the seasonal flu.
Identification
FluMist, according to the National Institutes of Health, or NIH, is a form of the seasonal flu vaccine. FluMist differs from other kinds of vaccines in that it is not injected. Instead, this type of vaccine is given in the form of a nasal spray, allowing it to access the immune system via the respiratory system. This mimics the route by which the flu virus normally infects the body.
Live Vaccines
FluMist is a live attenuated vaccine, Drugs.com explains. This means that the vaccine is made from a virus that is still alive but has been genetically modified to not be infectious. This means that the vaccine is able to generate an immune response but it cannot cause patients to actually come down with the flu. The immune response causes the body to produce special cells called memory T-cells. These cells allow for a rapid response to an influenza infection and enable the body to fight off the infection quickly. Because the strains of influenza that cause the seasonal flu change each year, FluMist has to be reformulated every year. It takes approximately two weeks for the vaccine to be fully effective after administration.
Indications
FluMist is approved for use in patients who are between the ages of 2 and 49, the NIH notes, as long as they are not pregnant and do not have certain medical conditions, such as AIDS or other problems that affect the immune system. It is recommended that adults older than 50 or people who have frequent contact with children younger than age 5 get some form of flu vaccine. People who live in correctional facilities, dormitories and other densely populated areas should also be vaccinated to avoid outbreaks.
Effectiveness
FluMist is an effective vaccine for the treatment of the seasonal flu. In 2005, MedImmune published a study comparing the effectiveness of FluMist to the injectable form of the flu vaccine. FluMist was 55 percent better at preventing seasonal flu than the injectable form of the seasonal flu vaccine. The relative effectiveness of FluMist may vary from year to year, however, because the strains of seasonal flu each year are different.
Side Effects
There are certain side effects associated with the use of FluMist, according to the NIH. Common mild side effects include nasal congestion or a runny nose, a headache and a sore throat. Patients may also develop a cough or chills. In some cases, patients can have a dangerous allergic reaction which leads to swelling throughout the body and hives. Allergic reactions to FluMist typically occur soon after the vaccine is given and can occur a few minutes to a few hours after the medication is administered.
