Before Administration
Once the flu vaccine has been manufactured, it is sent to health facilities approved for administering the vaccine. Each facility then stores the vaccine until it is time for administration. The Centers for Disease Control and Prevention (CDC) recommend the flu vaccine to all people as the most effective way in preventing the flu.
Regardless of the method of administration, once the flu virus is introduced to the immune system, the body begins building antibodies to fight off the foreign agent. This builds up the immunity to the virus, making it unlikely that an individual will get sick from the virus if exposed again. Each year the seasonal flu virus strain is slightly different. Novel strains of the flu virus, like influenza A, which appeared in humans in the spring of 2009, can present themselves periodically and require a new vaccine to prevent the spread of the illness. Laboratories, including those at the CDC, spend time identifying the seasonal flu strain and developing a new vaccine before the flu season officially hits. The base components of the vaccine are the same, but the live virus or inactive virus varies.
Dosing
With a patient in front of her, a health care professional will draw the correct dose of the vaccine using a syringe or nasal sprayer. The dose is dependent on the individual's age, weight and the method of administration. Examples of dosing, from the CDC, include 0.25cc for children six to 35 months via an injection, 0.5cc for children ages 36 months to nine years and 0.5mL for anyone over 36 months of age receiving an injection. The intranasal spray is administered to all individuals at 0.2cc. Some facilities may receive pre-filled syringes or nasal sprayers.
Administration
Infants and children who have never received a flu vaccine before will receive one injection followed by a booster injection four weeks later. Other children and adults will just receive one injection yearly. This is given by swabbing the arm or leg at the site of muscle tissue with antiseptic solution. The needle is then pushed into the skin until it reaches the muscle.
The nasal mist sprayer is placed below one nostril while the other is closed with a finger. The sprayer is activated by a press of the lid downward. This pushes the vaccine into the nasal passages, where the virus can make its way into the body.
