You can take steps -- none involves changing jobs -- to protect yourself and your family this flu-and-cold season.

The viruses that cause colds and flu spread primarily through hand-to-hand contact. John M. Lantz, dean of the University of San Francisco School of Nursing, advises washing hands frequently throughout the day; keeping hands away from the eyes, nose and mouth; avoiding crowds; eating well; and getting plenty of rest.

Kids too should wash their hands, especially before eating and after using the bathroom, blowing their noses, coughing or sneezing. But because soap and water so often aren't handy, many schools now teach students to cough or sneeze into a shoulder or elbow rather than a bare hand or tissue.

When choosing a day care facility, look for one with sound hygiene practices and clear rules about keeping sick children home.

At Marin Day Schools, which operates 17 day care centers serving many large employers in the San Francisco area, staff run toys through the dishwasher, preach hand-washing, and coach kids to cough and sneeze into their elbows. The centers also enforce a tough health policy: No child may come to day care with a cough, runny nose, fever, rash or diarrhea, and a child generally must be symptom-free for 24 hours before returning. For some kids, the policy can result in more time at home than at school.

Even medical school professors have tried to skirt the rules. But managing director Melinda Kanter-Levy says the centers hold firm. "It's stressful for everyone," she says. "It's really a balancing act between the needs of parents to drop off their kids so they can go to work, and good health for everybody."

No matter how conscientious the day care center, however, Thomas M. Ball, M.D., reminds us that sniffles are an inevitable -- and perhaps even beneficial -- passage of childhood.

"My wife and I never wanted to have one of those kids who had mucus always coming out of their nose," confesses Ball, father of a six-year-old boy and eight-year-old daughter. "But you just get used to it." And there may be an upside: Ball, an assistant professor of pediatrics at the University of Arizona, just published a study showing that babies who attend day care or have older siblings have less asthma later in life.

"One theory suggests that infections play an important role in the maturation of the immune system, causing the immune system to become less allergic," Ball explains. "Our study supported that view."

Here's what you need to know about the all-important flu shot.

Federal health officials monitor flu outbreaks worldwide throughout the year in an attempt to predict which flu strains will hit this continent in a given flu season. Each year's vaccine contains three flu strains, representing health officials' best guesses based on their monitoring. Usually the guesses are pretty accurate: The flu vaccine typically is about 90 percent effective at preventing flu.

This year's mix contains the A/Panama, A/New Caledonia, and B/Yamanashi strains. A flu shot takes about two weeks to become effective, and provides maximum protection one to two months after vaccination. The best time to get your shot, therefore, is now. This allows your immunity to peak during the most intense flu season: December to March.

The U.S. Advisory Committee on Immunization Practices advises everyone age 50 and older to get a flu shot this fall, down from age 65 in previous years. The ACIP also recommends flu shots for:

Children and adults with chronic heart, lung or kidney disease; diabetes; compromised immune systems; severe forms of anemia; and asthma.

Residents of nursing homes and other long-term care facilities.

Children and adolescents who are receiving long-term aspirin therapy and therefore may be at risk for developing Reye syndrome (a neurological disorder characterized by brain or liver damage) after flu infection.

Women who will be in the second or third trimester of pregnancy during the flu season.

Health care professionals and volunteers who work with high-risk patients.

Children and adults who live in a household with a person who fits into any of the above categories.

But if serial flu infections in your household this winter would eat up your sick leave, jeopardize your job, or derail a once-in-a-lifetime vacation, you might want to consider a flu shot for everyone in your family even if no one is on this list. Flu shots are approved for everyone older than six months. The only people who shouldn't get a flu shot are those with egg allergy (because a vaccine component is derived from eggs).

"Other than an egg allergy, there's no reason not to get a flu vaccine," says George Matula, M.D., an internist at the San Francisco Kaiser Permanente Medical Center.

A possible obstacle: The U.S. Food and Drug Administration and Centers for Disease Control and Prevention warned in June that manufacturing problems could cause vaccine shortages or delivery delays this fall.

If so, the agencies said they would call for voluntary efforts to ensure the vaccine goes first to those most likely to develop serious and life-threatening complications, including people who are over 65, are immunosuppressed or have a chronic disease.

Flu shots are offered each fall in private doctors' offices, HMO clinics, public health clinics, senior citizen centers and by some major grocery and drug store chains.

Unfortunately for the needle-shy, the vaccine nasal spray, Aviron's FluMist, isn't expected to reach the market until next flu season at the earliest. In FDA-supervised trials so far, the spray has proven 85 to 100 percent effective against the flu. An unexpected benefit: Children vaccinated with the spray had 30 percent fewer ear infections -- and a 35 percent reduction in related antibiotic use for ear infections.