We’ve all been told how important it is to get vaccinated against the flu every year. In fact, the 2017-18 flu season appears to be one of the most severe in recent years, based on the number of cases reported so far. But how does the flu vaccination actually work, and why should you get it?
Lindsay Schimpf, infection preventionist at Sharp Coronado Hospital, and Dr. Steven Green, chief medical officer of Sharp Rees-Stealy Medical Group, share important information you need to know about the flu vaccine.
What is the flu shot made of?
The flu shot works by exposing an individual to an inactivated form of the influenza virus, aka the “flu.” This exposure can stimulate an immune response that provides protection from the flu without causing illness.
There are many different strains of the flu, and the predominant strains that spread change each flu season. Every year the flu vaccine is reformulated and standardized by the U.S. Public Health Service to include three or four influenza strains that are predicted to circulate through the community during the upcoming season. So a typical flu vaccine is actually several vaccines rolled up in one, to protect against different strains.
How does the vaccine work?
The vaccines work by inducing specific antibody production, thus promoting immunity to the virus. It takes approximately two weeks after vaccination for the antibodies to develop in the body. While the vaccine will not cause the flu, it is not uncommon that vaccination can cause mild flu-like symptoms.
How effective it is?
Although there are reports that the 2017-2018 flu vaccine is only 10 to 20 percent effective, the Centers for Disease Control and Prevention (CDC) states that the 10 percent statistic is misleading. It is based on a report from Australia on a specific strain of influenza. The CDC states that the U.S. vaccine protects against multiple strains and estimates an effective rate of 40 to 60 percent.
Dr. Green advises everyone who is eligible to receive the vaccine to do so if they haven’t already.
“Even though we are not always sure the strains causing the epidemic will exactly match those in the vaccine, the downside is very small,” he says. “If someone is exposed to a strain in the vaccine they received, the infection will be less severe or not even noticeable.”
In addition, the antibodies from each year’s vaccine persist, so if someone gets vaccinated yearly, they will have more antibodies to more strains over time and be less likely to get the flu in future years as well.
Are there alternatives to the flu shot?
The Centers for Disease Control and Prevention (CDC) has recommended that the nasal flu vaccine, also known as the live attenuated influenza vaccine, should not be used during the 2017-18 flu season. Only the vaccine given by injection should be used.
Who should get vaccinated?
An annual flu shot is recommended for everyone 6 months of age and older (with rare exception), including pregnant women, people with chronic health conditions and older adults. Some children ages 6 months to 8 years who are getting vaccinated for the first time will require two doses of flu vaccine spaced at least 28 days apart. Talk to your doctor if you have had a severe allergic reaction to the flu vaccine or any ingredient in the vaccine (including gelatin, antibiotics or other ingredients); have ever had Guillain-Barré syndrome; or are not feeling well prior to receiving the flu shot.
Sharp offers ways to stay protected against the flu. Contact your doctor’s office directly to learn how to get vaccinated. For more information on vaccine availability and vaccination hours at local upcoming clinics, visit the San Diego Immunization Branch website or call 211.