DSI Newsletter: Influenza Vaccine

DSI Newsletters, Issue 18:
Influenza Vaccine: What You Need to Know

Why get vaccinated?
Influenza ("flu") is a serious infectious contagious disease. It is caused by a virus that spreads from infected persons via an aerosol route thru the nose and throat of others. Many people get hospitalized with influenza pneumonia and die each flu season needlessly. Our hospitals get filled up each flu season with patients suffering with respiratory tract infections. And to think, these are all preventable with a simple, safe flu shot.
Influenza (the flu) can cause the following symptoms:

fever
cough
sore throat
headache
chills
muscle aches

Anyone can get influenza. Most people are ill with influenza for only a few days, but some get much sicker and may need to be hospitalized. Influenza causes thousands of preventable deaths each year, mostly among the infirm and the elderly who are typically exposed to their granchildren. Vaccinating the grandchildren can prevent them from transmitting influenza to the grandparents. Vaccinating the grandparents can help protect them from the influenza virus that they may come into contact with. Vaccinating everyone in a community can greatly reduce the number of absenteeisms, hospitalizations, and deaths.
Influenza vaccine
Influenza viruses mutate (change their strain) often. Therefore, influenza vaccine is updated each year. Most years, the virus slowly drifts its strain (immunogenicity) to a new type. Some years, it abruptly shifts into a totally new form. Since the new virus is so different, it is more infectious and harmful and is responsible for more disease. Protective immunity develops about two weeks after getting the shot and may last for up to a year.
Some people who get flu vaccine may still get flu, but they will usually get a milder case than those who did not get the shot. This is dependent on host factors (how well your immune system deals with the vaccine) and how close the strain we immunize you with correlates with the strain that is circulating in your community and you become exposed to.
Flu vaccine may be given at the same time as other vaccines, including pneumococcal vaccine.
Who should get influenza vaccine?
Basically, everyone who wants to decrease their chances of becoming sick with the flu and/or decrease their chances of spreading the flu virus to others as it is common for young, healthy people to become infected with the virus and not feel sick. However, they can still be contagious and pass the virus to others.
High risk groups that we target to vaccinate first include: people six months of age and older at risk for getting a serious case of influenza or influenza complications, and people in close contact with them (including all household members), should get the vaccine.
An annual flu shot is recommended for:

Everyone 50 years of age or older.
Residents of long-term care facilities housing people with chronic medical conditions.
Anyone who has a long-term health problem with:

heart disease
lung disease
asthma
kidney disease
metabolic disease, such as diabetes
anemia, and other blood disorders

Anyone with a weakened immune system due to:

HIV/AIDS or another disease that affects the immune system
long-term treatment with drugs such as steroids
cancer treatment with x-rays or drugs

Anyone six months to 18 years of age on long-term aspirin treatment (who could develop Reye Syndrome if they catch influenza).
Pregnant women who will be past the third month of pregnancy during the flu season (usually November-March, but past March in some years).
Physicians, nurses, family members, or anyone else coming in close contact with people at risk of serious influenza.

An annual flu shot is also encouraged for:

Healthy children 6-23 months of age, and their household contacts and out-of-home caretakers.
Household contacts and out-of-home caretakers of infants less than six months of age.
People who provide essential community services.
People at high risk for flu complications who travel to the Southern hemisphere between April and September, or who travel to the tropics or in organized tourist groups at any time.
People living in dormitories or under other crowded conditions, to prevent outbreaks.
Anyone who wants to reduce their chance of catching influenza.

When should I get influenza vaccine?
Most people need only one flu shot each year to prevent influenza. Children under nine years old getting flu vaccine for the first time should get two shots, one month apart.
The best time to get a flu shot is in October or November. But because the flu season typically peaks between January and March, vaccination in December, or even later, can be beneficial in most years.
Some people should be vaccinated beginning in September or October: people 65 years of age and older, people at high risk from flu and its complications, household contacts of these groups, health care workers, and children under nine getting the flu shot for the first time. To make sure these people have access to available vaccine, others should wait until November.
Some people should talk with a doctor before getting influenza vaccine
Talk with a doctor before getting a flu shot if you:

ever had a serious allergic reaction to eggs or to a previous dose of influenza vaccine or
have a history of Guillain-Barre Syndrome (GBS)

If you have a fever or are severely ill at the time the shot is scheduled, you should probably wait until you recover before getting influenza vaccine. Talk to your doctor or nurse about whether to reschedule the vaccination.
What are the risks from influenza vaccine?
A vaccine, like any medicine, is capable of causing serious problems, such as severe allergic reactions. The risk of a vaccine causing serious harm, or death, is extremely small. Serious problems from flu vaccine are very rare. The viruses in the vaccine have been killed, so you cannot get influenza from the vaccine.
Mild problems:

soreness, redness, or swelling where the shot was given
fever
aches

If these problems occur, they usually begin soon after the shot and last one-two days.
Severe problems:

Life-threatening allergic reactions are very rare. If they do occur, it is within a few minutes to a few hours after the shot.
In 1976, swine flu vaccine was associated with a severe paralytic illness called Guillain-Barre Syndrome (GBS). Influenza vaccines since then have not been clearly linked to GBS. However, if there is a risk of GBS from current influenza vaccines, it is estimated at one or two cases per million persons vaccinated...much less than the risk of severe influenza, which can be prevented by vaccination.

What if there is a moderate or severe reaction?
What should I look for?

Any unusual condition, such as a high fever or behavior changes. Signs of a serious allergic reaction can include difficulty breathing, hoarseness or wheezing, hives, paleness, weakness, a fast heart beat, or dizziness.

What should I do?

Call a doctor, or get the person to a doctor right away.
Tell your doctor what happened, the date and time it happened, and when the vaccination was given.
Ask your doctor, nurse, or health department to report the reaction by filing a Vaccine Adverse Event Reporting System (VAERS) form, or call VAERS yourself at 1-800-822-7967, or visit their web site at www.vaers.org.

How can I learn more?
Ask your doctor or nurse. They can give you the vaccine package insert or suggest other sources of information.
Call your local or state health department.
Contact the Centers for Disease Control and Prevention (CDC):

call 1-800-232-2522 (English)
call 1-800-232-0233 (Spanish)
visit the National Immunization Program's web site at www.cdc.gov/nip

Return to Table of Contents