Vaccine Selection for the 2014-2015 Influenza Season
The United States Food and Drug Administration (FDA) has chosen the three influenza (flu) viruses for inclusion in the 2014-2015 seasonal flu vaccine based on recommendations from the World Health Organization (WHO). Each year, experts from FDA, WHO, U.S. Centers for Disease Control and Prevention (CDC) and other institutions study virus samples collected from around the world to identify the influenza viruses that are the most likely to cause illness during the upcoming flu season so that people can be protected against them through vaccination.
Seasonal Flu Vaccine
There are two types of flu vaccines:
- The "flu shot" - an inactivated vaccine (containing killed virus) that is given with a needle, usually in the arm. The flu shot is approved for use in people older than 6 months, including healthy people and people with chronic medical conditions.
There are three different flu shots available:
The nasal-spray flu vaccine - a vaccine made with live, weakened flu virus that is given as a nasal spray (sometimes called LAIV for "Live Attenuated Influenza Vaccine"). The viruses in the nasal spray vaccine do not cause the flu. LAIV is approved for use in healthy people 2 through 49 years of age who are not pregnant.
- A regular flu shot approved for people ages 6 months and older
- A high-dose flu shot approved for people 65 and older, and
- An intradermal flu shot approved for people 18 to 64 years of age
The seasonal flu vaccine for the 2014-2015 season protects against either three or four influenza viruses season. The traditional flu vaccine protects against three main viruses (called “trivalent” vaccines) that research indicates will cause the most illness this season. The 2014-2015 trivalent flu vaccine will protect against are influenza A (H1N1) virus, influenza A (H3N2) virus and an influenza B virus. The trivalent vaccine is offered for all different available flu shot options (regular, high-dose, and intradermal) and as the nasal-spray vaccine. There is also a flu vaccine available this season that protects against four different flu viruses (called “quadrivalent” vaccines). The quadrivalent vaccine is available as the regular flu shot and as a nasal-spray vaccine and it will protect against two influenza A viruses and two influenza B viruses. About 2 weeks after vaccination, antibodies that provide protection against influenza virus infection develop in the body.
Vaccination Prevents A Serious Disease
How Vaccines Work
Flu vaccines (the flu shot and the nasal-spray flu vaccine (LAlV)) cause antibodies to develop in the body. These antibodies provide protection against infection with the viruses that are in the vaccine.
Importance of Being Vaccinated
Influenza is a serious disease that can lead to hospitalization and sometimes even death. Every flu season is different, and influenza infection can affect people differently. Even healthy people can get very sick from the flu and spread it to others. Studies going back to 1976 have found that flu-related deaths ranged from a low of 3,000 to a high of about 49,000. During a regular flu season, about 90 percent of deaths occur in people 65 years and older. In addition, about half of all individuals who are infected with the flu will not have symptoms, but will be able to spread disease in the community. The "seasonal flu season" in the United States is usually from October through May each year.
During this time, flu viruses are circulating in the population. An annual seasonal flu vaccine (either the flu shot or the nasal-spray flu vaccine) is the best way to reduce the chances that you will get seasonal flu and lessen the chance that you will spread it to others. When more people get vaccinated against the flu, less flu can spread through that community.
Vaccine Effectiveness and Side Effects
The ability of a flu vaccine to protect a person depends on the age and health status of the person getting the vaccine, and the similarity or "match" between the viruses or virus in the vaccine and those in circulation.
Vaccine Side Effects (What to Expect)
Different side effects can be associated with the flu shot and LAIV.
The flu shot: The viruses in the flu shot are killed (inactivated), so you cannot get the flu from a flu shot. Some minor side effects that could occur are:
- Soreness, redness, or swelling where the shot was given
- Fever (low grade)
The nasal spray (also called LAIV or FluMist®): The viruses in the nasal-spray vaccine are weakened and do not cause severe symptoms often associated with influenza illness. (In clinical studies, transmission of vaccine viruses to close contacts has occurred only rarely.)
In children, side effects from LAIV (FluMist®) can include:
- runny nose
- muscle aches
In adults, side effects from LAIV (FluMist®) can include:
- runny nose
- sore throat
Over the last 50 years, seasonal flu vaccines have had very good safety track records. Hundreds of millions of Americans have safely received seasonal flu vaccines over the years. The most common side effects following flu vaccinations are mild. The Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA) closely monitor for any signs that flu vaccines are causing unexpected adverse events and work with state and local health officials to investigate any unusual events.
Video: Is The Flu Vaccine Safe?
Howard K. Koh, MD, MPH, the Assistant Secretary for Health at the U.S. Department of Health and Human Services (HHS), explains the importance of vaccine safety to maintain public health and public trust. The highest standards for vaccine safety are upheld and multiple monitoring systems are employed to ensure vaccine safety.