Quick facts about flu shots
Flu season is underway and there’s still time to get your shot. While it’s recommended to get vaccinated as early as possible, flu season tends to peak in January or later, depending on which part of the country you are living or traveling in, and it takes about two weeks for the vaccine to become effective. You will be protected if you get your shot now.
According to the Centers for Disease Control and Prevention, about 46 percent people in the United States aged 6 months and older were vaccinated during the 2015-16 flu season, down 1.5 percent from the previous year’s season. So if you’re hesitant or think the flu isn’t a serious enough illness for the inconvenience or you’ve succumbed to some of the myths surrounding it, let’s present a few facts from UCLA Health and from Dr. T. Warner Hudson, Medical Director of the Ronald Reagan UCLA Medical Center Occupational Health Facility and UCLA Medical Center, Santa Monica Hospital Employee Health Office.
What is influenza, or flu?
The flu is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. It can cause mild to severe illness, and at times can lead to death. The best way to prevent the flu is by getting a flu vaccine each year.
Signs and symptoms of flu
People who have the flu often feel some or all of these signs and symptoms:
- Fever or feeling feverish and chills (not all people with the flu will have a fever)
- Cold-like symptoms (cough, sore throat, runny or stuff nose)
- Muscle or body aches
- Vomiting and diarrhea (more common in children than adults).
How does the flu spread?
Most experts believe that flu viruses spread mainly by droplets made when people with flu cough, sneeze or talk. These droplets can land in the mouths or noses of people who are nearby. Less often, a person might also get flu by touching a surface or object that has flu virus on it, then touching their mouth, eyes or nose.
When are the periods of contagiousness?
You may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick. Most healthy adults may be able to infect others beginning one day before symptoms develop and up to 5 to 7 days after becoming sick. Some people, especially young children and people with weakened immune systems, may infect others for an even longer time.
What are some flu related complications?
Complications of flu can include bacterial pneumonia, ear infections, sinus infections, dehydration, and worsening of chronic medical conditions, such as congestive heart failure, asthma, or diabetes.
When should I get vaccinated?
“Flu vaccination should begin soon after vaccine becomes available,,” Hudson said. “However, as long as flu viruses are circulating, vaccination should continue to be offered throughout the flu season, even in January or later. While seasonal influenza outbreaks can happen as early as October, during most seasons influenza activity peaks in January or later. Since it takes about two weeks after vaccination for antibodies to develop in the body that protect against influenza virus infection, it is best that people get vaccinated so they are protected before influenza begins spreading in their community.”
Flu vaccine is produced by private manufacturers, and the timing of availability depends on when production is completed. Shipments began in August and will continue throughout October and November until all vaccine is distributed.
What are some myths surrounding the flu vaccine?
I worry I will get flu from the vaccine. “You cannot get flu from the flu shots,” Hudson said, adding that the vaccines are made from inactivated parts of flu viruses. There are other reasons people may get flu-like symptoms after a flu shot. They include:
- Because it takes about two weeks after a flu shot to become effective, it is still possible to get the flu in that window
- The flu shot is not 100% effective and its effectiveness depends on how well the vaccine matches the flu strains that are circulating each year.
- There are many other viral illnesses that produce flu-like symptoms during the cold and flu season, so you may have symptoms for some other virus
I worry it is not a safe vaccine. “Flu vaccine is an extremely safe vaccine,” Hudson said. “There is probably no other vaccine so highly monitored, scrutinized and used.” The Centers for Disease Control and Prevention estimates that U.S. manufacturers will have available 157 million to 168 million doses this season. And there is now a vaccine, called Flublok, for people with egg allergies. Side effects are minor from the flu shot. The viruses in the flu shot are killed (inactivated), so you cannot get the flu from the shot.
Some minor side effects that may occur are:
- Soreness, redness, or swelling where the shot was given
- Fever (low grade)
Who should not get vaccinated against seasonal flu?
Influenza vaccine is not approved for children younger than 6 months of age.
People who have had a severe allergic reaction to influenza vaccine should generally not be vaccinated.
There are some people who should not get a flu vaccine without first consulting a physician.
- People who have a moderate-to-severe illness with or without a fever (they should wait until they recover to get vaccinated).
- People with a history of Guillain–Barré Syndrome (a severe paralytic illness) 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’ve ever had Guillain-Barré Syndrome to help you decide if the vaccine is recommended for you.