St. Louis County will distribute 10,000 doses of H1N1 (swine flu) vaccine for free at five high schools on Saturday.

Preference will be given to county residents who fall into five high priority groups: pregnant women, children 6 months to 4 years old, caregivers for infants younger than 6 months, children from 5 to 18 years old who have underlying medical conditions like asthma or diabetes and health care workers.

Bring proof of county residency such as a driver's license or utility bill.

Line tickets will be distributed starting at 7 a.m. in a drive-through at the five high schools: Hazelwood West, Jennings, Lafayette, Lindbergh and Maplewood-Richmond Heights. Tickets at Maplewood-Richmond Heights will be distributed at Sunnen Products Company, 16 Sunnen Drive in Maplewood.

The line tickets will designate a morning or afternoon vaccine session between 8:30 a.m. and 4:30 p.m. For more information, visit saintlouiscountyflu.com.

Flu activity is widespread in Missouri and Illinois, and nearly all cases are the H1N1 (swine flu) strain. Rumors and myths about the flu are also swirling. Here is the latest information from the federal Centers for Disease Control and Prevention, the lead agency fighting the flu pandemic.

What is H1N1 (swine flu)?

The novel 2009 H1N1 is a new flu virus circulating among people worldwide. It first arrived in the U.S. last April and has since infected millions of Americans. It is sometimes called the swine flu because scientists originally thought the virus resembled those that can occur in pigs. Now it is believed the virus has genetic components of viruses that circulate in pigs, birds and humans.

What are the symptoms of H1N1?

Just like the regular flu, H1N1 is a respiratory virus that typically causes fever, cough, sore throat, body aches, runny nose, chills and fatigue. A few people have reported vomiting and diarrhea and not all cases have included a fever.

How serious is the H1N1 virus?

The virus has acted much like a typical flu in terms of severity. Most people who contract the virus have recovered without medical attention. There have been severe cases and about 300 deaths, primarily in high-risk populations. About two-thirds of people who are hospitalized with H1N1 have underlying medical conditions including asthma, pregnancy, diabetes or heart disease.

How does H1N1 flu compare to seasonal flu?

Seasonal and H1N1 flu can cause mild to severe illnesses and deaths. Every year 36,000 Americans die from flu. The H1N1 flu has disproportionately infected people ages 25 and younger. While most deaths from seasonal flu occur in people 65 and older, there have been fewer cases and deaths from H1N1 in that age group. There have been about 300 deaths from H1N1 since April, and more than half have been in people younger than 50. Other risk factors that can lead to complications from both types of flu include asthma, diabetes, heart disease, kidney disease, immune disorders and pregnancy.

How is H1N1 spread?

The virus is mainly spread through the air by coughing and sneezing. It can also more rarely be caught by touching an object like a doorknob that has virus on it and then transferring the virus to the nose or mouth. The virus can live for two to eight hours on surfaces.

How long is the virus contagious?

People with either type of flu can infect other people from one day before symptoms start to one week later. The CDC recommends staying home from work or school for at least 24 hours after you have been free of flu without using medication.

Why are pregnant women more vulnerable to flu?

Two reasons: their immune systems are compromised so their bodies don't reject the fetus, and lung capacity can be diminished by the growing fetus in later stages of pregnancy.

I think I have the flu. Should I go to the doctor?

Call your doctor first so waiting rooms and clinics do not become overcrowded and the virus does not spread further. Some symptoms require immediate medical attention, including difficulty breathing, severe dehydration, changes in consciousness, fever with a rash, symptoms that return after improving, chest pain, dizziness or persistent vomiting.

How is H1N1 treated?

Most people recover without treatment or with over-the-counter medicines. There are prescription anti-viral medications that can treat both types of flu. The drugs are typically reserved for severe cases or high-risk groups and are most effective within 48 hours of the start of symptoms.

How can I keep from catching the virus?

The best protection against both seasonal and H1N1 flu are the vaccines. Practicing good hygiene like hand washing and covering coughs and sneezes can also be somewhat effective. Alcohol-based hand gels are recommended if soap and water are not available.

I heard the vaccine was rushed. Is it safe?

The H1N1 flu vaccine was manufactured in the same time frame as the seasonal flu vaccine. Seasonal flu vaccines have a strong safety record and have been given hundreds of millions of times. Each season the flu shot contains three strains of flu virus that scientists predict will be circulating the globe. The 2009 H1N1 strain surfaced too late to be included in this season's regular flu shot, but it will likely be included in the 2010 seasonal flu vaccine.

Can I get the flu from the flu shot?

The virus in the shot is dead so it cannot cause the flu. Some people do experience side effects that mimic flu symptoms, including low fever, aches and nausea.

How is the vaccine made?

Once scientists identify the virus strain it is sent to manufacturers and injected into chicken eggs. The virus grows and multiplies before being removed, purified and processed into a vaccine that comes in either a shot or a nasal spray. The process generally takes five to six months.

Are there faster ways of making vaccines?

There is research going into new technologies that speed up the process. The CDC decided to use the standard method to produce the H1N1 vaccine.

What is the difference between the shot and the nasal spray?

The virus in the nasal spray vaccine is live but weakened. The virus in the vaccine multiplies in the nasal passages but cannot survive in the lungs. The virus triggers an immune response but rarely causes any symptoms. The nasal spray is only approved for people ages 2 to 49 who do not have underlying medical conditions including pregnancy, asthma, diabetes, cerebral palsy and heart disease.

Is there a shortage of flu vaccine?

The supply of H1N1 vaccines has been slower than expected. Missouri has received 250,000 doses and Illinois has received about 900,000. The CDC recommends that certain groups get vaccinated first: health care workers, pregnant women, caretakers of infants, people ages 6 months and 24 years and people 25 to 64 with chronic health conditions.

Do I still need the seasonal flu shot?

Yes. Nearly all flu viruses now circulating are the H1N1 variety. Scientists still predict that other flu strains will circulate this winter. There is still time to get a seasonal flu shot, since flu season generally peaks in January.

Who should not get vaccinated?

Anyone with severe egg allergies should not receive flu vaccines. Do not get the vaccine if you are currently sick.

Do the vaccines contain thimerosal or other preservatives?

The nasal spray does not contain preservatives. The shots come in two forms, multi-dose vials that contain preservatives to prevent cross contamination and single-dose vials that are preservative-free. Both Missouri and Illinois have lifted restrictions that prevent pregnant women and young children from receiving vaccines with preservatives.

Are there some people who should not receive this vaccine?

People who have a severe (life-threatening) allergy to chicken eggs or to any other substance in the vaccine should not be vaccinated.

Do the flu vaccines contain adjuvants?

No. Adjuvants are sometimes added to vaccines to make them stronger.

Who makes the vaccines?

The vaccines are made by CSL, MedImmune, Novartis and Sanofi Pasteur. The drug companies have a long record of producing seasonal flu vaccines using the same methods and distribution systems.

What are the side effects of the flu vaccine?

The most common side effects are mild and can include redness, swelling or soreness at the shot site. Health experts say the benefits of flu vaccines far outweigh the risks.

Why do kids under 10 need two doses of H1N1 vaccine?

Clinical trials have shown that children 6 months to 9 years old need two doses of H1N1 vaccine to produce a sufficient immune response to fight the virus. Young kids haven't been exposed to as many viruses and vaccines, and their immune systems need an extra dose to build up the antibodies to fight the flu.

I have had the flu since last spring. Should I still get the vaccine?

Yes. Flu symptoms (fever, cough, sore throat, aches) can be caused by many other viruses. And the majority of H1N1 cases are not laboratory confirmed. Unless you have lab results confirming H1N1 infection, you need to receive the vaccine to gain immunity. Anyone who has had a confirmed case of H1N1 doesn't need the vaccine. But doctors say it doesn't do any harm to receive the vaccine if you've already contracted the virus.

Some people in my family have received the vaccine but not others. Is that a problem?

"If everybody can't get vaccinated but you get a couple vaccinated, you're still protecting to a certain extent the ones who can't," said Ryan Moenster, an assistant professor at St. Louis College of Pharmacy.

How long does it take to gain immunity after getting the vaccine?

People produce antibodies that can fight the flu within a week to 10 days after receiving the vaccine.

Can the two vaccines be taken at the same time?

The shots can be taken on the same day, but the nasal spray should be taken three weeks apart.

Where can I get a flu vaccine?

St. Louis County residents in high priority groups can get free H1N1 vaccine on Saturday at five area high schools. For more information, visit www.saintlouiscountyflu.com. Madison County in Illinois holds public clinics for H1N1 nasal spray vaccine on Wednesday and Thursday mornings. Information is available at 618-692-8954. Other flu shot locators are available at www.flu.gov or 314-644-4358.



Get more online

Go to STLhealthandfitness.com for more questions and answers about swine flu.