The viruses that cause influenza change rapidly, making
different strains coexist on the planet at any given time.
Influenza vaccines are developed each year to protect people
from the three strains expected to be most prevalent.
ALL THE VIRUSES IN THE
VACCINE ARE KILLED, SO IT IS NOT POSSIBLE TO GET THE FLU FROM
THE VACCINE. MOST PEOPLE HAVE NO SIDE EFFECTS FROM THE
INFLUENZA VACCINE. SORENESS AT THE INJECTION SITE AND/OR MINOR
ACHES AND LOW GRADE FEVER MAY BE PRESENT FOR SEVERAL DAYS.
Since the immunity provided by the vaccine wanes after several
months, it is given at the beginning of the "flu
season"--usually late October or early November in the U.S.
People traveling to other countries should be aware that
influenza occurs throughout the year in tropical countries and
that the "flu season" for temperate countries in the Southern
Hemisphere is April to September.
Flu Shot Facts
Each year, the vaccine is updated to include the most current
strains of the virus. After getting a flu shot, a person's
body will create antibodies to fight the virus if exposed to
it. Antibodies against flu develop and provide protection
within 1 or 2 weeks after vaccination.
Flu Shot Myth
A common myth about the flu shot is that it can actually cause
the flu. But the flu vaccine in the United States is made from
killed influenza viruses, which means that it's impossible to
catch the flu by getting this vaccine.
Groups at High Risk
1. Persons > 50 years of age.
2. Residents of nursing homes and other chronic-care
facilities housing persons of any age with chronic medical
3. Adults and children who have chronic disorders of the
pulmonary or cardiovascular systems, including asthma.
4. Adults and children who have required regular medical
follow-up or hospitalization during the preceding year because
of chronic metabolic diseases (including diabetes mellitus),
renal dysfunction, anemias, or immunosuppression (including
immunosuppression caused by medications).
5. Children and teenagers (aged 6 months-18 years) who are
receiving long-term aspirin therapy and therefore might be at
risk of developing Reye's Syndrome after influenza infection.
6. Women who will be in the second or third trimester of
pregnancy during the influenza season.
People at High Risk
to Transmit Flu
1. Physicians, nurses, and other personnel in both hospital
and outpatient-care settings, including emergency response
2. Employees of nursing homes and chronic-care facilities who
have contact with patients or residents.
3. Employees of assisted living and other residences for
persons in high-risk groups.
4. Persons who provide home care to persons in high-risk
5. Household members (including children) of persons in
People Who SHOULD
NOT Have Flu Vaccinations
1. Influenza vaccine should not be administered to persons
known to have anaphylactic hypersensitivity to eggs or to
other vaccine components without first consulting a physician.
Use of an antiviral agent (amantadine or rimantadine) is an
option for prevention of influenza A in such persons.
2. Persons with acute febrile illnesses usually should not be
vaccinated until their symptoms have abated. However, minor
illnesses with or without fever do not contraindicate the use
of influenza vaccine, particularly among children with mild
upper respiratory tract infection or allergic rhinitis.
What Is Influenza?
Influenza vaccination protects people from contracting
influenza, a viral illness affecting the respiratory tract. In
the U.S., "flu" outbreaks typically occur between November and
April. Symptoms of influenza include fever, chills, muscle
aching, and cough. Although the illness usually only lasts 3
to 7 days, some people have more severe cases or complications
that require hospitalization. Thousands of people in the U.S.
die each year as the result of the flu or its complications.
Annual vaccination with influenza vaccine is considered the
single most important measure to prevent or to lessen the
severity of influenza infection and is strongly recommended
for high-risk groups. High-risk individuals should be
vaccinated every year. Most people achieve protection from
influenza vaccine approximately 2 weeks after receiving the
Who Else Should Have
a Flu Vaccination?
1. Persons infected with human immunodeficiency virus (HIV)
should be vaccinated because influenza symptoms might be
prolonged and the risk for complications increased for some
2. Breastfeeding mothers - Flu vaccine does not affect the
safety of mothers who are breastfeeding or their infants.
Breastfeeding does not adversely affect immune response and is
not a contraindication for vaccination.
3. Persons traveling to certain foreign countries (depends on
season and destination) should consider vaccination.
4. In routine years, vaccine is recommended for any person who
wishes to reduce his/her risk of acquiring influenza
infection. However, due to this year's anticipated vaccine
delay/shortage, vaccine should be prioritized for persons who
are at high-risk and their contacts.