Different Types of the Flu

Edgar Cruz, MD

Influenza (the flu) is a virus that infects the nose, throat, airways and the lungs. It is very contagious and is transmitted from person to person during coughing, sneezing, and even while speaking at a very close distance. The infection with the influenza virus occurs during the period from October through April.

The typical symptoms of the flu include fever, chills, muscle aches, nasal congestion, runny nose and difficulty breathing. In some instances, in vulnerable people like young children and older adults, it can even cause fulminant pneumonia. Every year in the United States approximately 200,000 people are hospitalized and 36,000 die from complications of the infection. Because of the fact that the infection is caused by a virus, it cannot be successfully treated with antibiotics.

Since the 1940’s a flu vaccine has been available to reduce or eliminate the symptoms of the flu. There are two types of vaccines. The vaccine with inactivated virus is developed in eggs. It is purified and it is administered as an injection. The vaccine with attenuated (debilitated) virus ”Flu Mist”, is also produced in eggs. This vaccine is administered as a nasal spray. Because the virus is attenuated, it cannot grow in the lungs but it can grow in the nasal cavity were it produces an excellent protective immune response. Both vaccines include the 3 most frequent types of virus that cause the infection during that year. The flu vaccine is administered each year because the circulating virus are different each year.

For the most part the flu vaccines are safe. There is a secondary effect that could be very serious. Because the vaccines are produced in eggs there might be a small amount of egg protein. The people that are allergic to eggs might develop an allergic reaction that is rarely fatal but that it can be very severe. For this reason people that are allergic to eggs should not receive the flu vaccine unless they are in a very high risk population and that the benefits of receiving the vaccine outweighs the risk of getting a severe flu infection.

The flu vaccine is usually administered right before the flu season starts during September and November. The vaccine can be administered during the flu season even through March. In a phone conversation with CDC (centers for Disease Control) personnel we were informed that as long the vaccine has not expired there is no definite time limit to administer the vaccine.

The vaccine could protect 70 to 90 of every 100 people from contracting a moderate to severe infection. Talk to your doctor and try to get the vaccine this year.