What is the flu?
Influenza, commonly known as flu, is a very contagious respiratory disease caused by the human influenza virus. There are two main types of flu:
Type A flu virus has many sub-types, and can infect both humans and animals. Because type A flu virus is constantly changing, it is responsible for global flu outbreaks that have killed millions of people such as Spanish Flu in (1918-1920) and Swine Flu (2009-2010).
Unlike type A, type B flu viruses only infects humans. Together, type A and B viruses cause seasonal flu epidemics each year.
When is the flu season?
Although flu viruses are active year round, they peak during fall and winter. It takes about 2 weeks for flu vaccines to work; therefore, it is better to get vaccinated early in the flu season before flu begins to spread.
How does flu spread?
Flu is spread from person to person through droplets in the air. When people with the flu cough, sneeze or talk, they can spread droplets as far as 6 feet away to other people. Sometimes, people can get infected by touching their mouth, nose or eyes after touching infected surfaces or objects. Once these droplets are inhaled, people usually develop symptoms after 1-4 days.
What are signs and symptoms of flu?
Fever
Chill and sweat
Cough
Sore throat
Runny/stuffy nose
Headache
Muscle ache
Fatigue
Vomiting and diarrhea in some people
Who are at high risk from flu?
Although anyone is at risk for the flu, some people are at higher risk for serious flu complications. These high risk individuals include:
Children
Pregnant women
People age 65 and older
People with weakened immune systems
People with heart, lung, or kidney disease
What does the flu vaccine do?
Flu vaccines are inactivated flu viruses which protect people from getting sick by stimulating their body’s immune systems to make antibodies to fight against the flu viruses.
There are 2 main types of flu vaccines:
Trivalent IIV (IIV3s): protect against 3 different seasonal influenza viruses
Quadrivalent IIVs (IIV4s) and RIV (RIV4): help to protect against four different flu viruses; two influenza A viruses and two influenza B viruses.
Common side effects include:
Soreness, redness, or swelling at the injection site
Low grade fever
Headache
Muscle ache
Why do we need to get vaccinated against the flu virus every year?
Flu is much more serious than people think. According to the Centers for Disease control and Prevention (CDC), 2017-2018 flu season was the most severe season in recent decades which resulted in thousands of deaths, and most of these flu-associated deaths were unvaccinated.
Flu vaccines are the most effective tool to protect people from getting sick or being hospitalized by the flu. Even if they get sick, the severity of flu in vaccinated people is also less compared to unvaccinated people.
Flu vaccine formulation is updated every year to keep up with constantly changing viruses; therefore, a new flu shot is needed annually for best protection.
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