infections
Influenza (Flu)
Vaccines for influenza
Annual vaccination is the best way to avoid getting influenza. There are two basic types of Influenza Vaccine : A vaccine that is given by injection and that contains inactivated (killed) influenza virus or pieces of the virus A vaccine that is inhaled as a nasal spray and that contains weakened (attenuated) live viruses Theinjected, inactivated vaccinecan be given to all people aged 6 months old or older, including pregnant women. A higher-dose inactivated influenza vaccine is available for people over age 65. The inactivated influenza vaccine is not given to People who had a severe allergic reaction to any influenza vaccine or one of its components Theinhaled, live-virus vaccineis used only in healthy people aged 2 to 49 years. It is not given to People who had a severe allergic reaction to any influenza vaccine or one of its components Pregnant women People with a weakened Overview of the Immune System (such as those who have AIDS or who take Children or adolescents who are takingaspirinover the long-term Children who are aged 2 to 4 years and have asthma or have had wheezing or asthma attacks in the last 12 months People who have taken an antiviral drug for influenza in the past 2 days The inhaled, live-virus vaccine was not recommended for the 2016-2017 and 2017-2018 flu seasons because of concerns that it was not as effective as the inactivated vaccines. However, the inhaled, live-virus vaccine has been reformulated and is now recommended equally with the inactivated vaccines. Some experts recommend the inactivated vaccine be used for children until the new live-virus vaccine has been studied more. Doctors typically postpone giving either vaccine to people who are ill at the time of vaccination. After the 1976 swine flu epidemic, in which millions of people received the influenza vaccine, a larger than usual number of people had a nerve disorder called Guillain-Barré Syndrome (GBS) . At the time, doctors thought the vaccine triggered Guillain-Barré syndrome, but more recent evidence makes this connection uncertain. However, to be safe, doctors use caution when giving another influenza vaccination to anyone who developed Guillain-Barré syndrome within 6 weeks of receiving the influenza vaccine. In such cases, doctors and the person weigh the risk of the person's getting influenza against the risk of possibly developing Guillain-Barré syndrome. People with a severe allergy to eggs may have an allergic reaction to the influenza vaccine because the vaccine is made from viruses grown in eggs. So doctors follow the following guidelines when giving people with an egg allergy the influenza vaccine: If the only reaction people have had to eggs is a rash ( Hives ), they can get the influenza vaccine. If people have had severe reactions to eggs (any symptom other than hives), they can get the influenza vaccine provided that the vaccine is given in a medical setting (such as a doctor's office, hospital, or clinic) and supervised by a health care practitioner who is able to recognize and manage severe allergic reactions. These reactions to eggs include swelling under the skin (angioedema), difficulty breathing (respiratory distress), light-headedness, repeated vomiting, and reactions that required anepinephrineshot or other emergency treatment. If people have had a severe allergic reaction (such as anaphylaxis) after they are given the influenza vaccine, they are not given the influenza vaccine again. Also, two vaccines that do not contain egg are available: one that can be used in people aged 18 and older and one that can be used in people aged 4 years and older. Influenza vaccines usually protect against three or four different strains of influenza virus. The strains of virus that cause influenza outbreaks change each year. Thus, different vaccines are developed each year to keep up with changes in the virus. Experts try to predict the strain of virus that will attack each year based on the strain of virus that predominated during the previous influenza season and the strain causing disease in other parts of the world. When the H and N proteins in the vaccine match those in the influenza strains causing the current epidemic, the vaccine decreases the rate of infection by 70 to 90% in healthy adults. In older people who live in long-term care facilities, the vaccine is less likely to prevent influenza, but it reduces the chances of developing pneumonia and of dying. Because the immune system becomes weaker as people age, a high-dose influenza vaccine has been designed specifically for people 65 years and older. This high-dose vaccine can stimulate a stronger Overview of the Immune System in older people. Other than occasional soreness at the injection site or, for the inhaled vaccine, a runny nose, side effects from the vaccine are rare. In the United States, vaccination takes place during the fall so that levels of antibodies are highest during the peak influenza months: November through March. For most people, about 2 weeks is needed for the vaccination to provide protection. Children aged 6 months to 8 years being given the influenza (flu) vaccine for the first time should be given two doses of the vaccine at least 4 weeks apart. Influenza vaccine can be given at the same time as Treatment . 