Immunization Update Series: Fortify Yourself Against Influenza

By John M. Weigand, M.D.
Director of Geriatric Services
Central Ohio Geriatrics

This month, Dr. Weigand continues his series about immunizations with the third of four articles about vaccines and how they protect us against disease. Please see our COG Blog archive for previous articles. The next immunization article is:

November: Shingles (Zoster) vaccine

October: Influenza 

September: Pneumonia 

August: Tetanus, diphtheria and whooping cough

Between August and November 2012, the recommendations of the Advisory Committee on Immunization Practices, or ACIP, will be reviewed and summarized for adults, especially those 65 and older. Each year the ACIP reviews the recommended schedule of adult immunizations to ensure it reflects the most current knowledge for licensed vaccines. 

Influenza Vaccine

Background

Influenza season generally extends from December until late March in Ohio and Midwest. The Centers for Disease Control report that between 5% and 20% of U.S. residents contract the flu each year. The influenza virus causes more than 200,000 hospitalizations and as many as 49,000 deaths annually. The U.S. Department of Health and Human Services identifies vaccination as the single most effective preventive measure available against influenza, preventing many illnesses, deaths and losses in work time and productivity. Influenza infections in persons older than 65 can result in serious complications leading to pneumonia, chronic disease exacerbations, hospitalizations and even death. When influenza deaths have been evaluated over the past several years, 90% of the deaths were in-patients older than 65. The number of Influenza illnesses and hospitalizations is estimated to rise during the 2012-2013 flu season because of the virility of the H3N2 strain that is threatening the United States.

There are two primary types of influenza infections each season, influenza A and influenza B. Influenza A causes more severe illness that influenza B. This year, two strains of particularly virulent influenza A and one strain of influenza B viruses are targeted by the trivalent vaccine. It is recommended that vaccinations be given in October and November to allow the development of immunity, which takes several weeks to occur. The only persons who should not get the influenza vaccine are those who:

1. have a severe allergy to eggs.

2. have a history of a severe reaction to the influenza vaccine (including Guillain-Barré syndrome).

3. are experiencing moderate to severe illness with fever at the time the vaccine is to be given.

4. are younger than 6 months of age (so, if you are reading this article, you do not qualify for this last exception).

The influenza vaccine comes in two forms: an inactivated form that is given by injection and a live, “weakened” virus form that is given via nasal spray. The nasal spray is approved for healthy patients between the ages of 5 and 49.

As a physician, I hear one of two reasons why patients refuse the influenza vaccine:

1. “I got the flu from the vaccine!” 

A common complaint is that the vaccine caused the person to get sick. The side effects of the flu vaccine include mild local soreness at the site of injection (10%-64%), low-grade fever, tiredness and muscle aches that may occur within 6-12 hours of the injection and last 1-2 days. Patients find it difficult to believe that these effects are not due to an actual viral infection, but to their bodies’ immune response protecting them from the serious effects of influenza. If you don’t get these side effects, you are still likely to be protected from an actual infection.

2. “I got the flu despite getting the vaccine!”   

Unfortunately in life, nothing is 100%, except death and taxes. The influenza vaccine cannot do anything about your tax bracket but it can prevent death! The vaccine prevents influenza in about 70%-90% of healthy persons younger than 65. Among elderly persons living outside long-term care facilities, such as nursing homes, and those persons with chronic medical conditions, the flu shot is 30%-70% effective in preventing hospitalization for pneumonia and influenza. Among elderly nursing home residents, the flu shot is most effective in preventing severe illness, secondary complications and deaths related to the flu. In this population, the shot can be 50%-60% effective in preventing hospitalization or pneumonia and 80% effective in preventing death from the flu.

Finally, other medications can be used to prevent and treat influenza infections. This year, only Tamiflu (oseltamivir) and Relenza (zanamivir) are effective. You should not be given either Symmetrel (amantadine) or Flumadine (rimantadine) because they are NOT effective against this year’s strain.

Many patients ask me about the effects of echinacea (an herbal product made from the purple coneflower) and zinc. Quite a few products are available over-the-counter that contain these ingredients and many patients swear by them. Unfortunately, research does not demonstrate that they are any more effective than placebo in preventing or treating colds or flu. If you choose to use these products, be sure to let your doctor know you are taking them if you are on prescription medication because of potential drug interactions, and do not exceed the recommended dose.

Of course, the two best ways of avoiding the flu this winter are to regularly wash your hands with soap and hot water (especially when you are out in public) and to avoid contact with friends or family members who are ill (watch out for the mistletoe)! 

Recommendation

• Annual vaccination against influenza is recommended for all persons 6 months of age and older. 

• Persons 6 months of age and older, including pregnant women, can receive the trivalent inactivated vaccine (TIV).

• Healthy, non-pregnant adults younger than age 50 years without high-risk medical conditions can receive either the intranasally administered live, attenuated influenza vaccine (LAIV or Flumist) or TIV. Health care personnel who care for severely immunocompromised persons (i.e., those who require care in a special protected environment) should receive TIV rather than LAIV. Other persons should receive TIV. 

The intramuscular- or intradermal-administered TIV are options for adults age 18-64 years.

• Adults age 65 or older can receive the standard dose TIV or the high-dose TIV (Fluzone High-Dose). 

Sources 

Recommended Adult Immunization Schedule – United States, 2012. JAMA, July 4, 2012, Vol 308, No. 1. Pg 22-27.

CDC Recommendations for Antiviral Medications Remain Unchanged: http://www.cdc.gov/media/haveyouheard/stories/Influenza_antiviral.html

Vaccine Virus Selection for the 2012-2013 Influenza Season: http://www.cdc.gov/flu/about/season/vaccine-selection.htm