By: Dr. Prasanna Honnavar

Influenza (flu) is a contagious respiratory infection caused by influenza viruses. The flu may range from mild to severe illness. Severe illness may result in hospitalization or death. High risk individuals include pregnant women, older people, young children, asthma, diabetes or heart and lung disease and health care workers.  There are two main types of influenza (flu) virus: Types A and B. The two types of influenza viruses (Type A and B) are responsible for seasonal flu epidemics each year. The best way to prevent flu is by getting vaccinated each year.

CDC recommends a yearly flu vaccine that can protect against the 3 or 4 common viruses which can cause potentially serious complications. Flu vaccination can protect from flu-related hospitalizations and even death. Some instances showed that few individuals get milder illness after vaccination. CDC recommends getting vaccinated by the end of October. It is not recommended to vaccinate infants younger than 6 months, however mother during pregnancy and infant care takers should be vaccinated.

How to avoid flu spreading

  • Avoid close contact with sick people.
  • Stay home for at least 24 hours once your fever has subsided.
  • When you cough or sneeze, cover your nose and mouth with a tissue paper, then throw it in the trash and wash your hands with soap and water or use an alcohol-based hand rub.
  • Avoid touching your eyes, nose and mouth.
  • Clean and disinfect surfaces and objects that may be contaminated with viruses.

Antiviral prescription.

Antiviral prescription drugs such as pills, liquid or an inhaled powder can make illness milder and shorten the time you are sick. CDC recommends prompt antiviral treatment of people who are severely ill with high-risk factors. Antiviral drugs work best for treatment when they are started within 48 hours of getting sick.

Flu-like symptoms

Symptoms of the flu can be a fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. Children may have vomiting and diarrhea. Few may have respiratory symptoms without a fever.

Flu Vaccination

Need of flu vaccination

The flu is a potentially serious disease which may result in high mortality. Flu seasons vary every year affecting millions of people, in which more than thousands get hospitalized and many people die from flu-related causes. Vaccination is the best way to help protect against the flu and reduce the risk related to the flu.

Mechanism of flu vaccines

After two weeks of vaccination our body produces antibodies that protects against upcoming season flu viruses. The vaccine may be traditional trivalent vaccine [influenza A (H1N1, H3N2), influenza B virus] or quadrivalent vaccines (trivalent vaccine + additional B virus)

What kinds of flu vaccines are available?

  • Inactivated influenza vaccine [IIV]
  • Recombinant influenza vaccine [RIV]
  • Live attenuated influenza vaccine (LAIV)

No preference is expressed for any influenza flu vaccine over another.

Trivalent flu vaccines Quadrivalent flu vaccines
·      Approved for people 65 years and older.

·      Contains a higher dose of antigen.

·      Made with adjuvant.

·     Made without adjuvant.

·     Manufactured using virus grown in eggs.

·     Different brands of this type of flu shot are available, and they are approved for different age groups.

·     Some are approved for children as young as 6 months of age.


Places to get a flu vaccine?

There are many places to get a flu vaccine including a doctor’s offices, clinics, health departments, pharmacies and college health centers, urgent care clinic, school, or even your workplace.

Vaccine Side Effects

A flu vaccine cannot cause the flu. The side effects may be very mild and short-lasting. Injectable vaccines may result soreness, redness, or swelling where the shot was given, fever (low grade), aches. The nasal spray vaccine may induce runny nose, wheezing, headache, vomiting, muscle aches, fever. In adults it may induce runny nose, headache, sore throat, and cough. Special consideration should be given to individuals who have a history of severe egg allergy. They should be vaccinated in a medical setting, supervised by a health care provider who is able to recognize and manage severe allergic reactions.

Reference: Centers for Disease Control and Prevention, National Center for Immunization and Respiratory Diseases (NCIRD), Atlanta.