Types of Flu Vaccine
The flu vaccine, like the polio vaccine in the past, is available in two main varieties. A vaccine that is made from killed virus is available in an injectable form, and a vaccine that is made from weakened live virus is available in the form of a nasal spray. These two types of vaccine work equally well.
The Flu Shot
The injectable form of the flu vaccine is made from killed flu virus. It is recommended for children down to age six months. Anyone who is eligible for the flu vaccine can request it from his or her doctor once the flu vaccine becomes available each winter season (usually in September or October).
You can safely receive the injectable form of the flu vaccine even if you are pregnant. You should not get the live flu vaccine (the nasal vaccine) during pregnancy.
The Nasal Spray Flu Vaccine
A live flu vaccine is available in the form of a nasal spray. This virus contains weakened but living flu virus, so the virus from the vaccine can actually multiply in the body after the vaccine is administered. However, the weakened virus in the vaccine cannot cause a full-blown flu infection.
The nasal flu vaccine that contains live virus (FluMist) can trigger an asthma attack for people with asthma. If you or your child has asthma, the injectable killed flu vaccine should be used.
The live flu vaccine cannot be given to children younger than two years or pregnant women. This live vaccine is not as widely available as the injectable form of the killed flu vaccine.
How Well Do Flu Vaccines Work?
The effectiveness of the flu vaccine depends on a lot of factors. As was mentioned previously, scientists have to predict the strains of the flu virus each year to tailor the annual vaccine. If the prediction is accurate, the flu vaccine for that year works exceptionally well. However, if the prediction is wrong, the usefulness of the flu vaccine is more limited.
Keep in mind that the flu vaccine can only protect you from the flu, not the common cold. There is no vaccine available for the common cold, and it is entirely possible to get sick from a cold even if you have gotten the flu vaccine.
In addition, the age of the person receiving the flu vaccine also influences how well the vaccine works. Older individuals generally respond more weakly to the vaccine than younger, healthy people. At the same time, older people are more vulnerable to having serious complications from the flu virus.
Even though the flu vaccine tends to work less well in older people, they still should get vaccinated because there is no better alternative in preventing the flu.