The single best way to protect against the flu is to get vaccinated each year. For your annual flu vaccine, come to our walk in clinic today, no appointment needed.
Why should people get vaccinated against the flu?
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. Over a period of 31 seasons between 1976 and 2007, estimates of flu-associated deaths in the United States range from a low of about 3,000 to a high of about 49,000 people. During a regular flu season, about 90 percent of deaths occur in people 65 years and older. The “seasonal flu season” in the United States can begin as early as October and last as late as May.
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.
How do flu vaccines work?
Flu vaccines (the flu shot and the nasal-spray flu vaccine (LAIV)) cause antibodies to develop in the body about two weeks after flu vaccination.
These antibodies provide protection against infection with the viruses that are in the vaccine.
The seasonal flu vaccine protects against three influenza viruses that research indicates will be most common during the upcoming season. Three kinds of influenza viruses commonly circulate among people today: influenza B viruses, influenza A (H1N1) viruses, and influenza A (H3N2) viruses. Each year, one flu virus of each kind is used to produce seasonal influenza vaccine.
What kinds of flu vaccines are available?
There are two types of 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 viruses 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.
Seasonal flu vaccines protect against the three influenza viruses (trivalent) or four influenza viruses (quadrivalent) that research indicates will be most common during the upcoming season. The viruses in the vaccine can change each year based on international surveillance and scientists’ estimations about which types and strains of viruses will circulate in a given year. About 2 weeks after vaccination, antibodies that provide protection against the influenza viruses in the vaccine develop in the body. Information specific to the 2015-2016 season including the flu vaccine formulation, can be found at 2016-2017 Flu Season.
Who Should Get Vaccinated This Season?
Everyone who is at least 6 months of age should get a flu vaccine this season. It’s especially important for some people to get vaccinated. Those people include the following:
- People who are at high risk of developing serious complications like pneumonia if they get sick with the flu. This includes:
- People who have certain medical conditions including asthma, diabetes, and chronic lung disease.
- Pregnant women.
- People 65 years and older
- People who live with or care for others who are high risk of developing serious complications. This includes:
- household contacts and caregivers of people with certain medical conditions including asthma, diabetes, and chronic lung disease.
A detailed list is available at Who Should Get Vaccinated Against Influenza. A complete list of health and age factors that are known to increase a person’s risk of developing serious complications from flu is available at People Who Are at High Risk of Developing Flu-Related Complications.
Who Should Not Be Vaccinated?
There are some people who should not get a flu vaccine without first consulting a physician. These include:
- People who have a severe allergy to chicken eggs.
- People who have had a severe reaction to an influenza vaccination.
- Children younger than 6 months of age (influenza vaccine is not approved for this age group), and
- People who have a moderate-to-severe illness with a fever (they should wait until they recover to get vaccinated.)
- People with a history of Guillain–Barré Syndrome (a severe paralytic illness, also called GBS) that occurred after receiving influenza vaccine and who are not at risk for severe illness from influenza should generally not receive vaccine. Tell your doctor if you ever had Guillain-Barré Syndrome. Your doctor will help you decide whether the vaccine is recommended for you.
When Should I Get Vaccinated?
CDC recommends that people get vaccinated against influenza as soon as flu season vaccine becomes available in their community. Influenza seasons are unpredictable, and can begin as early as October.
It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against the flu.
Flu vaccine is produced by private manufacturers, so availability depends on when production is completed. If everything goes as indicated by manufacturers, shipments are likely to begin in August and continue throughout September and October until all vaccine is distributed.
Why Do I Need a Flu Vaccine Every Year?
A flu vaccine is needed every year because flu viruses are constantly changing. It’s not unusual for new flu viruses to appear each year. The flu vaccine is formulated each year to keep up with the flu viruses as they change.
Also, multiple studies conducted over different seasons and across vaccine types and influenza virus subtypes have shown that the body’s immunity to influenza viruses (acquired either through natural infection or vaccination) declines over time.
Getting vaccinated each year provides the best protection against influenza throughout flu season.
Does flu vaccine work right away?
No. It takes about two weeks after vaccination for antibodies to develop in the body and provide protection against influenza virus infection. In the meantime, you are still at risk for getting the flu. That’s why it’s better to get vaccinated early in the fall, before the flu season really gets under way.
Can I get seasonal flu even though I got a flu vaccine this year?
Yes. The ability of flu vaccine to protect a person depends on two things: 1) the age and health status of the person getting vaccinated, and 2) the similarity or “match” between the virus strains in the vaccine and those circulating in the community. If the viruses in the vaccine and the influenza viruses circulating in the community are closely matched, vaccine effectiveness is higher. If they are not closely matched, vaccine effectiveness can be reduced. However, it’s important to remember that even when the viruses are not closely matched, the vaccine can still protect many people and prevent flu-related complications. Such protection is possible because antibodies made in response to the vaccine can provide some protection (called cross-protection) against different, but related strains of influenza viruses. For more information about vaccine effectiveness, visit How Well Does the Seasonal Flu Vaccine Work?