Vaccine a powerful weapon

The most important tool for fighting the everchanging flu virus is immunization by a killed virus vaccine licensed by FDA. The vaccine is made from highly purified, egg-grown viruses that have been made noninfectious.

Vaccination is available to anyone who wants to reduce their chances of getting the flu. Studies have shown the vaccine's effectiveness rate to be 70 to 90 percent in healthy young adults. In the elderly and in people with certain chronic illnesses, the vaccine sometimes doesn't prevent illness altogether, but it does reduce its severity and the risk of complications.

The government's Advisory Committee on Immunization Practices strongly recommends vaccination for the following high-risk groups:

• people aged 65 or older
• residents of nursing homes and other facilities that provide care for chronically ill persons
• people over the age of 6 months, including pregnant women, who have certain underlying medical conditions that required hospitalization or regular doctors' visits during the preceding year.

These conditions include:

• asthma, anemia, metabolic disease such as diabetes, or heart, lung or kidney disease
• impaired immune system due to HIV infection, treatment with drugs such as long-term steroids, or cancer treatment with radiation or chemotherapy
• children and teenagers (6 months to 18 years) who must take aspirin regularly and therefore may be at risk of developing Reye syndrome if they get the flu.

To reduce the risk of transmitting flu to high-risk persons--and to protect themselves from infection--the advisory committee recommends flu shots for people with regular close contact with high-risk groups. Such people include health-care workers, nursing home personnel, home-care providers, and children. Police, firefighters, and other community service providers may also find vaccination useful.

Because it takes the immune system about six to eight weeks to respond to vaccination, the best time to get the flu vaccine is mid-October to mid-November, before the December-to-March U.S. flu season hits.

The vaccine's most common side effect is soreness at the vaccination site for up to two days. Some people may experience post-shot fever, malaise, sore muscles, and other symptoms resembling the flu that can last for one to two days. Actually, the flu vaccine can't cause flu because it contains only inactivated viruses.

The vaccine should be repeated annually, since the immunity is believed to last only about a year, and because the vaccine's composition changes each year based on the flu strains scientists expect to be most common.

To decide which strains of influenza virus should be incorporated into the vaccine for the coming flu season, FDA's Vaccines and Related Biologicals Advisory Committee meets in late January each year to consider reports from national and international surveillance systems. A World Health Organization panel meets in Geneva in mid-February to make final recommendations for the next season's flu vaccine.

The strains are labeled by their type (A, B or C) and the place where the strain was isolated. In 1996, the predominant strains were A/Johannesberg, A/Texas, and B/Beijing. The anticipated strains for the 1996-1997 flu season are largely the same: A/Texas, A/Wuhan-like, and B/Beijing.

"In the not-too-distant future," says Iacuzio, "consumers may have alternatives to the flu shot, including different delivery methods like nasal drops or a spray." Major pharmaceutical companies, in cooperation with scientists representing NIH, FDA's Center for Biologics Evaluation and Research, and academia, are making significant strides, also, toward an even more protective vaccine.

Some people--but not many--should avoid the flu shot. People allergic to eggs and people with certain other allergies and medical problems like bronchitis or pneumonia should consult a doctor before getting a flu shot. And those with a high fever should not receive the vaccine until they feel better.

Pregnant women who have a high-risk condition should be immunized regardless of the stage of pregnancy; healthy pregnant women may also want to consult their health-care providers about being vaccinated.

In the rare cases when the vaccine is not advisable, two prescription drugs are available for prevention of type A influenza: Symmetrel (amantadine), approved by FDA in 1976, and Flumadine (rimantadine), approved by FDA in 1993. Either drug also can be used to reduce symptoms and shorten the illness if administered within 48 hours after symptoms appear.

If, despite precautions, you do get a cold or flu, besides taking an OTC medication if needed and as directed, drink fluids and get plenty of bed rest. "Your body is trying to attack the virus," Iacuzio says. "Give in, and give your body a chance to fight off the infection. It takes energy to do that."

Many people are convinced that vitamin C can prevent colds or relieve symptoms. There is no conclusive evidence of this, but the vitamin may reduce the severity or duration of symptoms, according to the National Institute of Allergy and Infectious Diseases. But taking vitamin C in large amounts over long periods can be harmful, sometimes causing diarrhea and distorting common medical tests of the urine and blood.

Another proposed therapy, interferon-alpha nasal spray, can prevent infection and illness but causes unacceptable side effects like nosebleeds, according to the institute.

Many patients have their own, unproven theories about what works. "As long as it's not harmful, why not try it?" says Iacuzio. "But be skeptical of something that hasn't been clinically proven in a well-designed, placebo-controlled study." So what about chicken soup? It may soothe a sore throat, unstuff clogged passageways, and hydrate a thirsty body. At the very least, according to Iacuzio, "It's good TLC. Psychologically, that's important when you're sick."