Flu Shot Facts & Side Effects (Updated for 2018-2019)
Flu Shot Facts & Side Effects (Updated for 2018-2019).
It only takes a few minutes, and has prevented more than 40,000 deaths over the last 13 years. We’ve all heard the advice to get the flu shot each fall. But is it really that important to do so?
The short answer: definitely yes.
A study published in 2015 estimated that the seasonal flu vaccine prevented more than 40,000 flu-associated deaths in the United States between 2005-2006 and 2013-2014. That’s significant, given the number of Americans the flu kills each year. Estimates from the Centers for Disease Control and Prevention (CDC) show that flu-associated deaths ranged from 12,000 (during the period of 2011 to 2012) to 56,000 (during 2012 to 2013). And the shot’s life-saving potential is most pronounced in seniors 65 and older and kids 6 months up to 5 years old.
What is the flu shot?
Flu shot is the best way to protect yourself and family from the flu symptomz that occur seasonally, but flu shot is a yearly vaccine administered to protect against the flu, or influenza. To break it down to a lay man understanding, “flu shot is a vaccine given with a needle, usually in the arm.” This help to protects against the three or four influenza viruses that research indicates will be most common during the season.
In the United States, flu shots are recommended for everyone ages 6 months and older, according to the Centers for Disease Control and Prevention. CDC recommends use of injectable influenza vaccines (including inactivated influenza vaccines and recombinant influenza vaccines) during 2017-2018.
How effective is the flu shot?
The protection provided by a flu vaccine 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. For more information, see Vaccine Effectiveness – How well does the Flu Vaccine Work. Strains of the flu virus are constantly changing, so a new flu vaccine is made each year. Scientists make the vaccine before the flu season starts by predicting which flu strains are likely to be the most common during the upcoming season.
According to medical study and research different flu shots are approved for different age groups., the flu can be a very serious illness, especially in young children, adults ages 65 and over, those with underlying health conditions, and pregnant women. “Since the flu virus frequently drifts in its genetic composition, you have to reformulate the vaccine, and this is one of the reasons that people have to [get a flu shot] on an annual basis,” said Dr. William Schaffner, a preventive medicine and infectious disease expert at Vanderbilt University School of Medicine.
What kinds of flu shots are there?
- Trivalent flu vaccines include:
a. Standard-dose trivalent shots (IIV3) that are manufactured using virus grown in eggs Most flu shots are given in the arm (muscle) with a needle. One trivalent vaccine formulation can be given with a jet injector, for persons aged 18 through 64 years.
- A high-dose trivalent shot, approved for people 65 and older.
- A recombinant trivalent shot that is egg-free, approved for people 18 years and older, including pregnant women.
- A trivalent flu shot made with adjuvant (an ingredient of a vaccine that helps create a stronger immune response in the patient’s body), approved for people 65 years of age and older (new this season).
2. Quadrivalent flu vaccines include:
- Quadrivalent flu shots approved for use in different age groups, including children as young as 6 months.
- An intradermal quadrivalent flu shot, which is injected into the skin instead of the muscle and uses a much smaller needle than the regular flu shot. It is approved for people 18 through 64 years of age.
- A quadrivalent flu shot containing virus grown in cell culture, which is approved for people 4 years of age and older.
- A recombinant quadrivalent flu shot approved for people 18 years of age and older, including pregnant women (new this season).
The composition of the 2018-2019 flu shot will be slightly different from last season’s flu shot. Specifically, there will be a different strain of the H3N2 virus and a different strain of the influenza B virus in this season’s flu shot, compared with last season’s shot. According to the CDC, the 2018-2019 trivalent flu shot will contain the following strains of the flu virus:
A/Michigan/45/2015 (H1N1)pdm09-like virus — This is the H1N1 component that is the same as last year’s flu shot.
A/Singapore/INFIMH-16–0019/2016 A(H3N2)-like virus — This is the H3N2 component that is different from last year’s flu shot.
B/Colorado/06/2017-like (B/Victoria lineage) virus — This is the influenza B strain component that is the different from last year’s shot.
The CDC said it was making a change to the influenza B component of the vaccine because of an increase in circulation of influenza B strains that have “drifted” genetically, compared with earlier strains. The agency said it was making a change to the H3N2 component to address concerns that this strain of the virus changes somewhat when it’s grown in eggs during the manufacturing process. When the new H3N2 component is grown in eggs, it appears more similar to circulating flu viruses, compared with the strain that was used in last year’s vaccine.
Is the nasal spray recommended?
After not recommending the flu nasal spray for the past two years, the CDC is once again recommending the spray during the 2018-2019 flu season. For both the 2016-2017 season and the 2017-2018 season, the CDC omitted the nasal spray, called FluMist, from its list of recommended flu vaccine types. That’s because data showed that the nasal spray was not very effective at preventing flu from 2013 to 2016, the CDC said.
But this year, the maker of FluMist, AstraZeneca, said that it had slightly changed the formulation of the spray, and a study of U.S. children who received the spray suggested that the new formulation produced a better immune response than the old one. It was partly based on this data that the CDC added the nasal spray back to its list of recommended flu shot types. (The nasal spray is licensed for healthy people ages 2 to 49, but it is not recommended for pregnant women.)
After reviewing the same data that the CDC used to make its decision, “the AAP recommends children receive the injectable form of the vaccine, which was shown to be more consistently effective against most strains of the flu virus over the past several flu seasons,” compared with the nasal spray, the organization said in a statement .
But the AAP said that the nasal spray could be used this year as a “last resort” for children who would otherwise not receive a flu shot. “If you get the nasal spray vaccine, just be aware that, depending on the performance of the new vaccine formulation, there might be a chance you will not be fully protected,” Dr. Flor Munoz, a member of the AAP Committee on Infectious Diseases, said in the statement. “The efficacy of this new [nasal spray] formulation has not yet been determined.”
When should you get a flu shot?
Exactly when the flu season starts and ends is unpredictable, so health officials recommend that people get their flu shot in early fall, preferably by the end of October, the CDC says. Flu activity typically peaks in January or February. “We’d like to get as many people protected against influenza before influenza becomes active in communities across the country,” Schaffner said.
Each season’s flu shot expires in June of that year, but Schaffner said that he would consider it “too late” to get a flu vaccine after March, unless a person is traveling to the Southern Hemisphere (where the flu season will be starting). After vaccination, it takes a person about two weeks to build up immunity against the flu.
People can visit the CDC’s HealthMap Vaccine Finder to find flu shot locations, although they should call the location ahead of time to see if they have the vaccine in stock.
How effective is the flu vaccine?
The effectiveness of the seasonal flu vaccine depends upon several factors, including how well the flu strains in the vaccine match the strains in circulation. Some studies show that when strains in the vaccine are a good match with the ones that are circulating, vaccinated individuals are 60 percent less likely to catch the flu than people who aren’t vaccinated, according to the CDC. Flu vaccine effectiveness can also vary depending on the person being vaccinated — the vaccine tends to work best in healthy adults and older children, and less well in older adults.
But other studies suggest that individuals who do get sick develop less serve symptoms if they are vaccinated. A 2013 study published in the journal Clinical Infectious Diseases found that people who got the flu shot were less likely to be hospitalized with the flu.
Are flu vaccines safe for pregnant women?
Yes. Studies show flu vaccines are safe for women in any stage of pregnancy, the CDC says. There are several reasons why it’s important for pregnant women to get a flu shot, Schaffner said. “Pregnant women, when they get influenza, have a tendency to get a more severe disease,” and are at increased risk for complications and hospitalization from the disease, Schaffner said.
What are the side effects?
According to the CDC, mild side effects from the flu shot include soreness, redness or swelling at the injection site, low-grade fever and aches. Only about 1 percent to 2 percent of people who get a flu shot will have fever as a side effect, Schaffner said.
Rare but serious side effects can occur, including allergic reactions. Symptoms of serious side effects include difficulty breathing, swelling around the eyes or lips, hives, racing heart, dizziness and high fever. If you experience serious side effects, you should seek medical care immediately, the CDC says.
For children, side effects from the flu nasal spray can include runny nose, wheezing, headache, vomiting, muscle aches and fever. For adults, side effects include runny nose, headache, sore throat and cough. These side effects last a short time compared to the actual flu illness, the CDC says.
Can you get the flu from the flu shot?
You can catch the flu from the vaccine. The vaccine is made from an inactivated virus that can’t transmit infection. So people who get sick after receiving a flu vaccination were going to get sick anyway… But people assume that because they got sick after getting the vaccine, the shot caused their illness.
The viruses in the flu shot are killed, so people cannot get the flu from a flu vaccine. However, because it takes about two weeks for people to build up immunity after they get the flu vaccine, some people may catch the flu shortly after their vaccinated, if they are exposed to the flu during this time period.
Some people may also mistakenly attribute symptoms of a cold to the vaccine, Schaffner said. The nasal spray vaccine contains a “live attenuated” flu virus, but the virus is weakened so that it cannot cause the flu. The viruses in the nasal spray can’t replicate in the warm temperatures of the lungs and other parts in the body. However, because temperatures in the nose are colder, the virus causes a small infection in the nose. This infection does not cause symptoms in most people, but in some people, it causes symptoms such as runny nose and sore throat, Schaffner said.
Who should not get a flu vaccine?
Children younger than 6 months cannot get a flu shot. Those who’ve had a severe allergic reaction to a flu vaccine in the past should generally not be vaccinated, the CDC says. Be sure to tell your doctor before getting vaccinated if you: Have had a life-threatening allergic reaction to a dose of the flu vaccine or any ingredient in the vaccine (like eggs or gelatin) Have had Guillain-Barré Syndrome (an immune system disorder). (You should wait until the fever is gone.) However, if you have minor illness, like a mild cold or a headache, you can still get a flu shot, Schaffner said. “The vaccine does perfectly well in those folks.”