What You Can Do About the Flu
October 11, 2005
Last reviewed and revised by Faculty of Harvard Medical School on September 21, 2009
By Mary Pickett, M.D.
Harvard Medical School
There's a chill in the air, and schoolchildren are beginning to come home with the first colds of the year. Any time now, we will be into the thick of flu season. It is inevitable that some of us will suffer through the flu this year. The new H1N1 strain of flu has caused cases in all states within the United States, and has increased concern about flu. Nonetheless, planning will help you.
You can greatly lower your chances of getting the flu if you get a flu shot. A separate vaccination against H1N1 influenza A ("swine flu") can lower your risk for getting H1N1 flu or its complications.
Although testing is available to distinguish H1N1 influenza from other virus strains, the test is expensive and does not often result in a change in how your doctor cares for you and counsels you. Many doctors offices are not offering H1N1 tests due to this principle. The test is useful for a person who has a complication and needs to be hospitalized.
Several drugs are also available to help prevent and treat the flu. It is nice to have them as options, but these medicines aren't perfect solutions for the flu. After reviewing who needs a flu shot, I will tell you the not-so-simple story of flu medicines. They are not very commonly used.
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Who Needs a Flu Shot?
The flu shot (influenza vaccine) is our best protection against the flu. Most people who get the flu shot avoid the flu entirely, and those who get the shot and then get flu have milder symptoms than they would have otherwise.
The seasonal flu shot became available in September this year. Get your shot as soon as you can, so it can protect you through the whole flu season. Most flu occurs in December, January and February.
In order to get the best protection, you need to get a new flu shot against seasonal flu every year. Flu viruses shift their form over time, so every new flu season is unique. Each year, experts produce a new batch of influenza vaccine after sleuthing and careful prediction. This way, the protein mixture that is used in the vaccine can prepare us for the very strains of flu that are likely to be active during our flu season.
It is especially important to get vaccinated against seasonal flu if you:
- Are age 50 or older
- Are a child between age six months and just before your 19th birthday especially if you require daily aspirin treatment, which helps prevent viral infections and avoid a complication known as Reye's syndrome)
- Have diabetes, heart or lung disease, or impaired neurological function
- Have a brain injury or nerve problem that puts you at risk to aspirate (inhale saliva) when you have an illness with cough
- Have any medical illness that will require you to repeatedly visit a clinic or hospital during the flu season
- Work in a clinic or hospital
- Have an illness that suppresses your immune system, such as HIV
- You take medicine that suppresses your immune system, such as prednisone
- Are pregnant or you expect you may become pregnant before flu season ends. The flu shot is now recommended even for women who are in the first trimester of pregnancy, although this was not always the case.
- You live in a nursing home or facility shared by frail or elderly people
- You care for someone who is frail, or someone who is too young to receive the flu shot (an infant less than 6 months old)
This year, there are two vaccines. The H1N1 vaccination has been approved. Ideally, you should get a single dose of this vaccine as soon as it becomes available. Recent research has shown that one shot of this vaccine is effective against flu, so one shot (not two, as health experts initially predicted) is recommended.
It is recommended that you get an H1N1 influenza vaccine if you:
- Are pregnant
- Live with or care closely for one or more infants who are under the age of 6 months
- Work in an ambulance, clinic or hospital
- Are between the ages of 6 months and 24 years
- Are between the ages of 25 and 64 and you have a chronic medical illness, such as diabetes, lung disease, or one that suppresses your immune system.
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Flu Vaccine in a Nose Spray
The seasonal and the novel H1N1 flu vaccines are also available as a nasal spray. The nose spray form for seasonal flu prevention (FluMist) is just as effective as the shot. The nasal spray for novel H1N1 also appears to be just as effective. However, it is brand new and has limited testing. The nose spray form for the H1N1 pandemic flu strain will start to be available in early October 2009.
While the shot contains proteins (not whole virus particles), the nose spray contains a live virus that is similar to real seasonal and novel H1N1 flu. This weakened virus strain, called an "attenuated" virus, has been specially cultivated by flu experts. It is too weak to cause symptoms, but it exposes your immune system to the same surface proteins that you would encounter if you were exposed to the real flu. This triggers your immune system to prepare itself so it can fight the flu.
A few specific groups of people can become ill even with this weakened virus, so they can't receive the nasal flu vaccine. You shouldn't get the nose spray if you are:
- Younger than 2 years
- Age 50 or older
- A person with a weak immune system
- In frequent contact with a person who has a weak immune system
- A person with asthma
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Pills for Prevention Not Practical
If you do not get the flu shot and you are exposed to someone with cough, fever and muscle aches that suggest influenza, you may become interested in medicines that can prevent the flu.
Three available medicines have been approved by the U.S. Food and Drug Administration for use after exposure to the flu, to prevent flu infection. They are oseltamivir (Tamiflu), amantadine (Symmetrel) and rimantadine (Flumadine). These three medicines are able to kill influenza virus particles as long as the strain of virus you have is not one that has become drug-resistant. Only oseltamivir is recommended to prevent the flu, and only in specific cases. The good news is that it has the fewest side effects, and it works against more varieties of influenza than do the other drugs.
If you take oseltamivir for a large portion of the flu season, it can help to keep you from getting the flu. However, flu season is a long season. If you want a pill to prevent flu for you, then you will have to take it for many days. This can get expensive and inconvenient.
The main study that demonstrated a protective benefit from oseltamivir had people taking daily medication for a full six weeks.
Without oseltamivir, about one out of every 21 adults would have developed the flu in this study. Six weeks of oseltamivir whittled this statistic down to one person out of every 77 or so. Certainly, some individuals benefited from having the oseltamivir. However, many more people took the medicine and never really needed it. Scientists counted and concluded that at least 25 treated people or roughly 1,200 separate doses of oseltamivir (costing more than $8,000) were needed in order to successfully prevent a single case of flu.
For six weeks of treatment, the cost of this drug for an individual is approximately $300. Most people don't think the drug is worth the money. Certainly, if you can receive a flu shot, vaccination is a better way to get protection.
Some people try using oseltamivir for 10 days, if a person in their household gets sick with the flu. This shorter course of treatment costs about $75. This can help to protect you, but it can only protect you for those 10 days. If flu continues to be passed around within your community (in buses, in your grocery, or other places you may go), then you are still at risk. Just like a bicycle helmet, antiviral drugs can protect you only at the times you are using them.
Oseltamivir may be useful for prevention of H1N1 ("swine") flu, for you if you have a close exposure (a person with a flu infection living in your home, or in your care), if you have a risk factor for complications of flu, and if you have not received the H1N1 vaccine.
Prevention drugs can be useful for people who spend most of their time in a closed community, such as a nursing home. Some experts recommend preventive treatment during a seasonal flu outbreak even if most or all of the individuals in a nursing home have received the seasonal flu vaccine, to give these older individuals the maximum protection. In order for prevention to work best, everyone in the facility needs to take oseltamivir at the same time, and they need to start treatment right after flu hits the center. This way, the flu outbreak in the facility does not last very long, and a reasonably short course of antiviral medicine can be used to protect the residents.
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Medicines for Flu Treatment
If you receive the flu shot, you probably will have a very mild flu or no flu this year. If you don't get the flu shot, a select group of people might benefit from treatment with an antiviral medicine at the start of flu symptoms.
Oseltamivir and another antiviral drug, zanamivir (Relenza), can be considered for treatment of most strains of the seasonal flu. Some strains of flu have developed drug resistance. That's another reason why preventing the flu is so important to help stop drug resistance.
Oseltamivir can also be used to treat H1N1 flu. If treatment is received within 48 hours of the onset of symptoms, it may lowers the risk for complications, such as pneumonia, dehydration, and severe bronchitis. For people who are at high risk for complications (such as a person with a suppressed immune system), or for people who have needed to be hospitalized, treatment is recommended.
Usual seasonal flu infection causes symptoms of fever, aches, cough, headache and nasal symptoms that last for about five days. If your symptoms are truly coming from seasonal flu, an antiviral medicine can reduce the length of symptoms to four days or so, so it can be a little bit helpful. However, these drugs work only if you take your first dose within 48 hours after the start of your symptoms. Also, they don't have an obvious benefit if your symptoms are mild, without a high fever on the first day of symptoms.
H1N1 symptoms are similar to flu, usually resulting in fever, cough, and sore throat but occasionally also involving nausea, vomiting or diarrhea. Between the ages of 24 and 49 you are most vulnerable to getting H1N1 flu. Older people are thought to have immunity against a variety of H1N1 strains from exposures that occurred decades ago, so they are not as likely to get H1N1 flu or its complications.
The cost of treatment is about $75 for oseltamivir and somewhat less for zanamivir.
Both flu medicines can cause side effects. Oseltamivir causes nausea and vomiting in one out of every six people who take the medicine. Zanamivir (an inhaled medicine) can cause cough or wheeze, nose or throat irritation and should not be used by a person with lung disease. Neither of these drugs can be used during pregnancy.
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Back to Basics
Most people do not use antiviral medicines to treat the flu. For almost anyone with flu, acetaminophen (Tylenol) is helpful. It can improve fever and chills, reduce aches, and help headaches.
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Mary Pickett, M.D. is a lecturer for Harvard Medical School and an associate professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Oregon.