Influenza viruses cause seasonal influenza, commonly called “the flu,” which infects the nose, throat, and lungs. Unlike many other viral respiratory infections, such as the common cold, the flu can cause severe illness and life-threatening complications in many people. In the United States, on average 5- 20% of the population get the flu, more than 200,000 people are hospitalized from flu-related complications, and about 36,000 patients die each year from influenza. Persons most susceptible to severe morbidity and mortality (and the best candidates for the flu vaccine, discussed below) include persons with asthma, chronic lung or heart disease, as well as persons with morbid obesity, endocrine, liver, neurological, or kidney disorders. Patients with weak immune systems (from chemotherapy or specific immune disorders) also should receive the flu vaccine yearly. In past years, the CDC (Centers for Disease Control and Prevention) recommended that all children <5, adults >65, and pregnant women, regardless of underlying medical problems receive the flu vaccine. However, after the H1N1 pandemic of 2009-2010, they are now recommending universal flu vaccination for all citizens >6months of age.
The flu vaccine is updated annually based on World Health Organization (WHO) recommendations from 4 international laboratories: in the US, the UK, Australia, and Japan. Their recommendations are based on year round surveillance and study conducted at 130 national influenza centers in 101 countries.
Everyone should get vaccinated this year even if they received a seasonal vaccine last year because the vaccine viruses are always updated. Immunity sets in about two weeks after vaccination and the flu vaccine provides protection that lasts through the flu season. The decision is supported by evidence that influenza vaccination is a safe and effective preventive health measure with potential benefits across all age groups. Even healthy adults with no previously identified risk factors can develop influenza-related complications, including adults ages 19-49 years old. This group has never had specific recommendations for vaccination in previous influenza seasons, however they were unusually affected by the 2009 H1N1 pandemic.
Contraindications to the vaccine include severe egg allergy, previous severe reaction to the flu vaccine, or fever.
Besides the vaccine, other ways to prevent the flu this season include keeping your nose and mouth covered with a tissue when you cough or sneeze. Also make sure to dispose of the tissue properly after its use, and to wash your hands often with soap and water. If soap and water are not available, use an alcohol-based hand rub. Avoid touching your eyes, nose and mouth. Try to avoid close contact with sick people. If you are sick with flu–like illness, CDC recommends that you stay home for at least 24 hours after your fever is gone except to get medical care or for other necessities. (Your fever should be gone without the use of a fever-reducing medicine.) While sick, limit contact with others as much as possible to keep from infecting them.
There are treatments available for the flu; the most commonly used is Oseltamivir, with the trade name Tamiflu. Oseltamivir is most effective at treating the flu, or lessening its symptoms, if given within 48 hours of the onset of disease. It can be given to prevent disease in close contacts of a known case, but only if those contacts are high risk – specifically those persons listed in the first paragraph. As with any medication Oseltamivir has side effects, most involving the gastrointestinal system including nausea, vomiting and abdominal pain, however, some side effects can be severe. A doctor should always prescribe this medication specifically to every patient before it is taken. There are many over the counter, and holistic preparations that may help with symptoms of the flu. However, you should always check with a doctor before taking anything.
Both as a previous patient and now as a physician, before risking the trial and tribulations of the actual flu, I highly encourage you to get your flu shot!