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What is the flu shot? The traditional influenza vaccine is a shot that must be given in the shoulder muscle. It contains no live material whatsoever, so it cannot cause any human infection.
The vaccine is made by harvesting three different strains of influenza. The live viruses are grown in chicken eggs, then killed with formaldehyde, further chopped into split pieces using chemicals and further purified. It is then put into a precisely concentrated liquid that can be injected into humans to produce immunity without producing any illness.
This manufacturing process is very labor intensive. The vaccine for this winter began production in March. As a result, once a vaccine shortage is detected, it is impossible for the manufacturer to make more vaccine in time for this winter. Currently there is only one U.S. manufacturer of this vaccine: Aventis-Pasteur. Despite the importance of this vaccine, each year millions of doses made by Aventis go unused and must be thrown away. Doses cannot be reused the following year. In 2002-03, 12 million doses were discarded, at a loss to the company of more than $120 million. It is therefore important to make an accurate guess of the vaccine demand each year and then to make enough vaccine to fill that need, but not excess vaccine that will only be discarded. Doses cannot be stockpiled and saved from year to year, because the circulating influenza viruses rapidly change, so that each year a brand new formulation must be made.
In the United States, no more than 80 million doses are used each year. Unfortunately this number means that more than half the people who should get the vaccine do not get it - not because of any shortages, but simply because they do not ask for it. Despite the medical need for more people to be vaccinated, millions of doses are thrown away each year, at a huge loss to manufacturers.
Beginning in 2003, a new live virus vaccine was approved in the United States. It is best known to doctors as LAIV (live attenuated influenza vaccine) or FluMist. It is made by MedImmune, located in Gaithersburg, Md. This vaccine has the advantage of being given as a squirt into the nose, not a shot. So there are no needles involved. However it can only be used in people from ages 5 to 50 years old who are healthy - without medical illnesses. This is unfortunate because 90 percent of the deaths from influenza occur in people older than 65. Children ages 6 months to 2 years are also a large risk group. Other large risk factors for hospitalization and death from influenza include diabetes, heart disease, cancer and emphysema. Unfortunately, this new vaccine cannot be used for any of the people in the risk groups mentioned above - the exact groups who are at highest risk of death from influenza.
Why is there a shortage?
This year, careful planning was done to insure adequate supplies. Aventis planned to produce roughly 50 million doses, and Chiron Corporation was to supply another 50 million doses from its plant in the United Kingdom. Unfortunately, it was determined that the Chiron doses were contaminated and therefore unsafe for use. The 50 million doses will be destroyed and are now unavailable to us. There was no way to foresee this shortage. To make up for this, we would have had to know of the problem in March 2004, so Adventis could have made an adequate supply. By the time there was any indication of a problem in the United Kingdom vaccine, it was far too late.
Still, this year 58 million doses have been produced and are available from Aventis. Since we generally use 70 to 80 million doses, this means that some people will have to go without the Aventis shot this year, but if only people at the highest risk tier are vaccinated, there should still be adequate vaccine supplies. It is not time to panic, since there are still 24 million doses of standard flu shots that have not yet been distributed. More will become available in the next six weeks.
Understandably, then, we need healthy persons whose age is greater than 2 and less than 65 to refrain from getting vaccinated this year, so that those at greater risk can receive their vaccine.
Who really needs a vaccination?
Physicians and hospitals have been strictly forbidden by the Delaware Department of Public Health to immunize any person not specifically on the list below. At this point, only people who meet one of these criteria can receive the standard flu shot:
• All children aged 6 to 23 months. It is important to note these children are the most important group of all. Their risk of hospitalization with influenza is twice as high as even those people older than 65 who have emphysema;
• Adults aged 65 years and older;
• People aged 2 to 64 years with underlying chronic medical conditions. This would include people with any history of heart attack, heart failure, chronic lung disease, diabetes, kidney disease, blood disorders like sickle cell anemia, cancer, organ transplant recipients, and those with HIV/AIDS;
• All women who will be pregnant during the influenza season;
• Residents of nursing homes and long-term care facilities;
• Children aged 6 months to 18 years who are on chronic aspirin therapy.
There are three other categories of people who should be vaccinated, but it is preferred that these people receive the newer live nose spray vaccine:
• Health-care workers involved in direct patient care;
• Out-of-home care givers to the sick and elderly
• Household contacts of children aged under 6 months - though LAIV is an option for these people
Who should not receive a shot?
• Healthy people ages 2 to 65 without chronic aspirin therapy and without any chronic medical condition as listed above.
Who should get LAIV?
Only people who are healthy, without medical diseases and age 5 to 50 should get this vaccine. Due to the shortage of supply, this vaccine should be targeted to visiting nurses, most doctors and nurses, and paramedics who have direct patient contact on a daily basis but who do not have contact with extremely immune compromised patients like those with in an organ transplant unit or bone marrow transplant unit. People who live in a house with those at high risk - including if you live with someone who has HIV/AIDS - can get this live vaccine. The person with the high-risk condition - including HIV/AIDS - should get the regular flu shot. Three million doses of LAIV are available this year.
People who cannot receive the live vaccine are those who are pregnant, people who have chronic medical illnesses, people on chronic aspirin, and people with asthma. Remember that no one who has any severe allergy to chicken eggs can get either influenza vaccine, because they are both made using eggs.
When to worry?
Not now. Typically we see very small numbers of influenza cases beginning in the third week of December. They peak in late January and diminish in February, with very little influenza activity after that. But cases do continue well through March and April. It only takes two weeks to get an immune response to either vaccine, so that vaccination for those at highest risk even in late December is still adequate. When vaccine is available, it is appropriate to vaccinate people through the winter and through the entire month of March.
What else can I do?
Keep in mind that you can only get influenza if someone else gives it to you. You cannot acquire it from nature, only from another infected person. People transmit the virus for about five days while they are sick. The virus is transmitted in the small mist particles that come from the nose and mouth during a sneeze or cough. People will also transmit the virus on their hands by rubbing their nose, then touching other people, such as with a handshake.
You can protect yourself by avoiding crowded events where other sick people are likely to transmit the virus. Unfortunately this means that to be the most careful, you might want to skip large meetings and parties if you are at highest risk of flu. Large Christmas gatherings and New Year’s Eve parties, unfortunately, are the perfect time and place for influenza transmission. Very small children should forego play groups and day-care settings if possible. If you keep your baby at home, the only way he can get infected is if you give the germ to him. If at all possible, keep children under 6 months at home, and vaccinate those older than 6 months.
People should learn to cover their mouths and noses with a tissue when sneezing or coughing. People need to stay at home when they are sick. You should not go to work or school, where you will perform poorly anyway, and you will only serve as a great risk of infection to all your coworkers.
Finally, people should wash their hands after contact with other people, even handshaking. Soap and water for 30 seconds, or any alcohol-containing hand disinfectant is good for this. And one should avoid touching the hands to the eyes, nose, or mouth. It is by these routes that the germs on the hands will infect your body.
What if I get sick?
First, know the difference between the common cold and true influenza. If you think you have signs of influenza, contact your doctor immediately. If caught within the first 48 hours of illness, you can be given viral medication that will make your illness much less severe, and of shorter duration.
Is influenza there now?
No. Normally, there will be very few cases even in late December. As of now, 41 states including Delaware and all of our neighbors - New Jersey, Maryland, Pennsylvania, Virginia, North Carolina and Washington, D.C. - have not had a single case of influenza. The closest states that have had at least one case are New York, Indiana and Michigan. Count on seeing a surge in nationwide influenza cases in January.
Where can I get the vaccine?
For now, there will be no public distribution of vaccine by the Department of Public Health clinics, local pharmacies or supermarkets. Beebe Medical Center will not have vaccine for public immunization. Only your private physician will have a limited number of doses that will be given to only persons at the highest risk of death from influenza. Throughout November, December and January, keep checking with your local physician to see if new doses have arrived. The Department of Public Health is expected to reopen vaccination clinics within the next six weeks as new supplies become available.
What’s the bottom line?
There is no reason to be more fearful this year than any prior year. There is absolutely nothing special or different about the actual influenza germ this year that should make vaccination any more important this year than any prior year. As an infectious disease specialist I am always glad when influenza gets the attention it deserves, but we need to avoid undo panic.
At this point with the standard shot and LAIV combined, we should have almost 80 percent of the number of doses of vaccine that are used in this country every year. By state ordinance, physicians and hospitals are now forbidden to give vaccine to people not fitting the high-risk criteria mentioned above. If we restrict vaccines to those people, then we will prevent influenza deaths. Young healthy people should not request vaccine, but should avoid influenza by avoiding crowds and washing their hands. We all owe it to our neighbors to stay home when we are sick, and to cover the mouth and nose when we sneeze or cough. For those people who become ill, make sure to call your doctor immediately because treatment is available, but will have no benefit if you’ve been ill for more than 2 days.
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