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Quadrivalent Influenza Vaccine


The common belief is that influenza only spreads during the rainy season, but influenza can spread during any season of the year. It does not only affect small children or people with weak immune systems; it can spread among people of every age. Even those with good health can get infected and pass on the virus to others. The symptoms might be minimal for some, but in many cases, influenza patients are hospitalized and many lose their lives from complications.

Getting to Know Influenza

Every year, there are between 250,000 and 500,000 people around the world who pass away from influenza. In Thailand, 1000 to 2000 people per 100,000 suffer from the virus per year. Unlike the common cold, symptoms of influenza last longer and are more severe. Patients with influenza are at risk of suffering from complications and those with chronic diseases are at an even higher risk of their diseases becoming worse. Life-threatening complications from influenza include pneumonia, bronchitis, and severe repercussions to the heart, including atherosclerosis, and damage to the central nervous system.

There are three types of influenza viruses – A, B and C. Each can cause an instant infection in the respiratory system. The infection starts from the nose and throat before spreading down towards the windpipe and lungs.

The spread of various types of the influenza virus through the years have made it difficult to predict which types will spread in any given season. In the past, Influenza A was the most common. But since the year 2000, Influenza B has spread even more and is proven to be as lethal as its counterpart. In Thailand, the spread of Influenza B has increased every year. As with influenza A, influenza B is equally capable of hospitalizing people and can be just as lethal.

Quadrivalent Influenza Vaccine

Since the influenza virus types were identified in 1993, the influenza vaccine is continually redeveloped. In 2012, the World Health Organization (WHO) required the addition of  influenza B protection into the vaccine, making it more efficient. Thus, the Quadrivalent Influenza Vaccine was introduced, capable of protecting against these four types of influenza:

  1. Influenza A/H1N1
  2. Influenza A/H3N2
  3. Influenza B – Type 1
  4. Influenza B – Type 2

Worldwide research has shown that the Quadrivalent Influenza Vaccine is more effective in preventing influenza.

  • In England, scientific studies have shown that the Quadrivalent vaccine is 18 percent more effective than the old vaccine.
  • After the United States started administering the Quadrivalent Influenza Vaccine, the number of influenza patients decreased by 1.3 million per year. The number of people being hospitalized was reduced by 12,472 and more than 663 lives were saved.
  • If the United States continues using the Quadrivalent Influenza Vaccine for the next 20 years, more than 13.3 people can be spared from influenza. Up to 113,000 people will not be hospitalized and more than 13,200 lives can be saved. The research also shows that the cost of hospitalizing influenza patients can will save approximately  31,000 million dollars, while other expenses associated with the virus can decrease by 600 million dollars.

Why should you get vaccinated annually?

Everyone should get vaccinated annually before every winter or rainy season, especially those who are at risk for complications. The immune system your body has against influenza weakens every few months while the influenza virus continually evolves. By getting vaccinated annually, your immune system is kept at a high level and is able to protect your body against the latest types of the influenza virus.

You can get vaccinated at any age, starting at six months old. Even women who are pregnant or breastfeeding can get vaccinated with the quadrivalent influenza vaccine.

Who is higher risk for complications from influenza?

Those who are at risk of developing complications from influenza include:

  • Small children ages 2-5 years old
  • Adults over 65 years of age
  • Pregnant women and women who have given birth within the past two weeks
  • People who are in need of constant care or are suffering from chronic diseases such as asthma and diabetes

What are the benefits of the Quadrivalent Influenza Vaccine?

Other than preventing four types of influenza viruses, the quadrivalent influenza vaccine also has the following benefits:

  1. Better prevention against the influenza B virus
  2. Protecting your loved ones or those around you from contracting the virus
  3. May make certain other illnesses milder
  4. Reduces the risks of dangerous complications that can arise from influenza, especially for small children and patients suffering from chronic illnesses
  5. Reduces the use of medication and antibiotics
  6. Reduces hospitalizations and therefore costs
  7. Reduces time away from work or school
  8. Reduces the number of deaths

For more information:

Vaccination and Travel Medicine Center, Samitivej Sukhumvit Tel. 0-2022-8742-3

Vaccination Center, Samitivej Srinakarin Tel. 0-2378-9085


  1. WHO Influenza. Available from Accessed on 1 September, 2015.
  2. Thai NIH – Circulating Influenza B lineages Thailand 2003-2013.  Accessed on 1 September, 2015.
  3. “The potential Cost-Effectiveness of Quadrivalent vs Trivalent influenza vaccine in elderly people and clinical risk group in the UK” – A lifetime Multi-Cohort Model, Laure-Anne Van Bellinghen,Genevieve Meier,Iise Van Vlaenderen. Accessed on 1 September, 2015.
  4. “Public health impact of including two lineages of influenza B in a quadrivalent seasonal influenza vaccine”, Carrie Reeda, Martin I. Meltzerb, Lyn Finelli and Anthony Fiorea.  Accessed on 1 September, 2015.
  5. “Cost-effectiveness of quadrivalent versus trivalent influenza vaccine in the United States”, P.T. de Boer, . Crépey, R. Pitman, B. Macabeo, A. Chit, and M.J. Postma. Accessed on 1 September, 2015.

“Key Facts about Seasonal Flu Vaccine”, Centers for Disease Control and Prevention. Accessed on 1 September, 2015.

Photo Credit: MIKI Yoshihito. (#mikiyoshihito) via Compfight cc

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