Flu season is here again, and the Clatsop County Public Health Department urges the public to protect itself from this preventable illness.

Influenza is caused by a virus spread person-to-person, through the air and on hard surfaces in droplets from sneezes and coughs. Illness from the flu can last up to 10 days and include such symptoms as sneezing, coughing, runny nose, congestion, fever, muscle aches and headache.

For some people, the flu can be a very serious, even deadly disease, which could lead to secondary infections such as pneumonia. Every flu season is different, and influenza can affect people differently. Even healthy children and adults can get very sick from the flu and spread it to others.

Each year, scientists determine the three flu strains that are likely to cause the most disease and include them in the flu vaccination for that season. The 2011-12 seasonal flu shot protects against the same strains as last year, but people who had a flu vaccination last year should also get a seasonal flu shot this year, as immunity may have worn off.

Seasonal flu vaccine is manufactured by strict federal standards and thoroughly tested before it is offered to the public.

Vaccination is the most effective way to avoid catching the flu virus, and the best way to protect yourself and your community from illness. The Centers for Disease Control and Prevention recommends everyone aged 6 months and older receive an annual influenza vaccination. Children 6 months through 8 years may need two doses depending on previous flu vaccine history, so it is important to talk to your provider.

A seasonal flu vaccination is especially recommended for people with chronic medical conditions, pregnant women, people living or caring for babies six months and younger or people who are unable to be vaccinated because of health reasons, and all health care workers.

These preventive measures can help stop flu and other diseases from circulating: cover a cough and sneeze; wash hands often with soap and warm water; stay home when sick; and keep surfaces clean.

Clatsop County Public Health has flu vaccines available by appointment for children 6 months and older and adults. Shots are $30 for regular vaccine and $44 for high-dose vaccine. Some insurance can be billed, and vaccine can be made available at reduced or no cost for those without insurance or who otherwise cannot afford it.

• For information, and to set up an appointment, call (503) 325-8500.

To locate other flu shot clinics, go to flu.oregon.gov or call the Oregon Flu Hotline at (800) 978-3040.