What is influenza?
Influenza (also called
the “flu”) is a contagious respiratory illness caused by influenza viruses that
infect the nose, throat and lungs. It can cause mild to severe illness and, at
times, can lead to death. The best way to prevent the flu is by getting a flu vaccine
and symptoms of flu
People who have the
flu often have some or all of these signs and symptoms:
Fever or feeling feverish/chills
Runny or stuffy nose
Muscle or body aches
Fatigue (very tired)
Rarely, vomiting and diarrhea
Influenza viruses are
spread from person to person. This can happen when an infected person coughs or
sneezes. Coughs and sneezes produce virus-laden droplets that can spread up to three
feet through the air. Flu also can be spread when droplets from a cough or
sneeze land on objects like doorknobs, light switches, etc. If others touch the
objects and then touch their own mouth or nose (or someone else's mouth or
nose) before washing their hands, the virus can be spread.
You can pass the flu
to someone else both before and while you are sick. Adults may be able to
infect others beginning one day before symptoms develop and up
to five to seven days after becoming sick. Some people,
especially young children and people with weakened immune systems, might be
able to infect others for an even longer time.
Certain people are at
greater risk for serious complications if they get the flu. This includes older
people, young children, pregnant women and people with certain health
conditions such as asthma, diabetes or heart disease (http://www.cdc.gov/flu/about/disease/high_risk.htm).
The severity of flu
seasons vary widely from one season to the next. The number of flu-associated
deaths in the United States usually ranges from 3,000 to 49,000 deaths per year
but can be much higher if a new strain develops to which no one is immune.
The severity of flu
season depends on many things, including:
What flu viruses are spreading;
How much flu vaccine is available;
When vaccine is available;
How many people get vaccinated; and
How well the flu vaccine is matched to flu viruses that are
Complications of flu
can include pneumonia, ear infections, sinus infections, dehydration and
worsening of chronic medical conditions, such as congestive heart failure,
asthma or diabetes.
Prevent seasonal flu: Get vaccinated
The single best way to
prevent the flu is to get a flu vaccine each season. There are several flu vaccine
options for the 2017-18 flu
season. Traditional flu vaccines made to protect against three different flu
viruses (called “trivalent” vaccines) are available. In addition, flu vaccines
made to protect against four different flu viruses (called “quadrivalent”
vaccines) also are available.
to get vaccinated against seasonal flu
Yearly flu vaccination
should begin soon after flu vaccine is available and, ideally, by October.
However, getting vaccinated even later can be protective, as long as flu
viruses are circulating. While seasonal influenza outbreaks can happen as early
as October, influenza activity most often peaks in January or
later. Since it takes about two weeks after vaccination for antibodies to
develop in the body that protect against influenza virus infection, it is best
that people get vaccinated to be protected before influenza begins spreading in
WHO SHOULD GET
VACCINATED THIS SEASON?
Everyone 6 months of
age and older should get a flu vaccine every season. This recommendation has
been in place since Feb. 24, 2010, when CDC’s Advisory Committee on
Immunization Practices (ACIP) voted for “universal” flu vaccination in the
United States to expand protection against the flu to more people. Vaccination
to prevent influenza is particularly important for people who are at high risk
of serious complications from influenza.
of the nasal spray seasonal flu vaccine
For the 2017–18
season, ACIP has recommended that the live attenuated influenza vaccine (LAIV4
or FluMist) should not be used.