The flu can leave you with muscle aches, fever, a cough, sore throat, headache, and an exhaustion that can knock you flat for weeks. But getting an annual flu shot will cut your chances of coming down with the viral illness by about half, according to the Centers for Disease Control and Prevention. And if you do get sick, a flu shot can protect you by making your illness milder.
HealthCentral talked to William Schaffner, M.D., consultant to the CDC’s Advisory Committee on Immunization Practices (ACIP), and a professor of medicine in the division of infectious diseases at Vanderbilt University School of Medicine in Nashville. We asked for his advice on which flu shot to get and the best time of year to get it.
William Schaffner, M.D.
Q: Years ago there was just one flu shot available. Now there are many. Which one should I ask for?
Dr. Schaffner: Getting the shot now, whether at your doctor’s office, pharmacy, place of worship, or even at the airport, will protect you until early spring, when the virus subsides. Depending upon where you go, you won’t always have a choice about which flu shot to get. But if you do, you should know that some flu vaccines protect better than others.
There are multiple strains of the flu, and they change over time. That’s the major reason we have to change the vaccine every year. Some vaccines have three components (called trivalent) and others have four components (called quadrivalent).
The trivalent protects you against three strains of the flu: two As (H1N1 and H3N2) and one B. The quadrivalent protects against an additional B strain.
The A strains are associated with the large outbreaks. For the most part they are the dominant viruses and they occur first. Their cousins, the B viruses, smolder along and are the ones that are the most prominent at the end of the flu season in March and April. They cause illness just as severe as the A viruses.
For people 65 and up, there’s extensive evidence for the Fluzone High-Dose, which contains four times the standard shot’s flu-antigen dose and is meant to induce a stronger immune response for better protection against the flu. A study involving more than 30,000 people age 65 and up found that it was 24 percent more effective than the standard vaccine. Fluad, which was new in the U.S. last year, is also specially designed for seniors.
People 50 and up are a priority group for flu vaccination because they may be more likely to have chronic medical conditions, such as cardiovascular disease, diabetes, or chronic lung disease, that put them at higher risk of severe sickness if they catch the flu.
Children under the age of 8 who have never gotten the flu shot before need two doses of the flu shot separated by one month.
Babies can get a flu shot starting at 6 months old and pregnant women should get vaccinated now to protect their infants from the flu for several months after they are born.
What’s not recommended any longer is the nasal spray vaccine, though it’s still on the market. The CDC says it shouldn’t be used because of concerns about how well it works.
Q. When should I get the shot?
Dr. Schaffner: The national immunization push begins in late September and revs up through October. There is no official “too early,” though I would not get vaccinated in August. On the other side of the coin, people may wonder: Is it too late to get vaccinated in December? The answer is no. It takes two weeks for protection to be maximized, and the flu generally peaks in February in most parts of the country.
Q. Can I get another flu shot in February as a booster?
Dr. Schaffner: That’s a frequently asked question, but a second shot doesn’t really improve your immune response. But if you’re 65 or older, consider also getting a pneumonia vaccine, which can decrease your risk of flu-related complications.
Q. What if I got the wrong flu shot? Can I get it again?
Dr. Schaffner: No. It’s better to be a bit mindful about which shot you’re getting before you roll up your sleeve, especially for people who are older and will be better protected with the high dose. Still, any flu shot is better than none.
Q. Can I get sick from the flu shot?
Dr. Schaffner: You can’t get the flu from the flu vaccine. It’s extraordinarily safe. Hundreds of millions of doses are given, and about 1 or 2 percent of people get a degree of fever for about a day. There’s some soreness at the inoculation site. The reason this myth was propagated is because a lot of people get vaccinated in October, November, and December, during cold and flu season. So a person may get the vaccine on Monday and then get a cold. But it has nothing to do with the flu shot.
Q. How effective is the flu shot?
Dr. Schaffner: It’s going to vary depending on which population you look at. Younger people have a stronger immune system, so they respond better. Older people do not have as robust an immune system, so the regular vaccine does not protect them as well. Sometimes my patients tell me, “You gave me the vaccine and I got the flu.” But I tell them that the vaccine actually made it less likely that they would be hospitalized.
Although the flu shot is imperfect, it’s the very best thing you can do to protect yourself from influenza, year in and year out. Even if you’re not completely protected, the vaccine will likely make your illness less severe. Influenza is a serious disease, and this is a simple, inexpensive thing to do.