What is the Difference Between Trivalent and Quadrivalent Flu Vaccine

The key difference between trivalent and quadrivalent flu vaccine is that trivalent flu vaccine provides protection against three different flu viruses, including two influenza A viruses and one influenza B virus, while quadrivalent flu vaccine provides protection against four different flu viruses, including two influenza A viruses and two influenza B viruses.

Influenza is commonly called the flu virus. Flu is an infectious disease caused by influenza viruses. The symptoms often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. Vaccination is the most effective way to prevent influenza infection. Influenza vaccines also called “flu shots”. There are totally seven types of flu vaccines. Trivalent and quadrivalent flu vaccines are two types of influenza vaccines that contain inactivated forms of influenza viruses.

CONTENTS

1. Overview and Key Difference
2. What is Trivalent Flu Vaccine
3. What is Quadrivalent Flu Vaccine
4. Similarities – Trivalent and Quadrivalent
5. Trivalent vs Quadrivalent Flu Vaccine
6. Summary – Trivalent vs Quadrivalent

What is Trivalent Flu Vaccine?

Trivalent flu vaccine is designed to protect against three different flu viruses, including two influenza A viruses and one influenza B virus. This vaccine usually protects people against three strains of influenza virus: influenza A (H1N1), influenza A (H3N2), and Influenza B (B/Washington/02/2019 like strain).

Trivalent flu vaccines are egg-grown flu vaccines. They are propagated in embryonated chicken eggs and inactivated with formaldehyde. Therefore, this vaccine contains inactivated form of influenza viruses. They are administrated by a needle into a muscle in the patient’s arm.  Sometimes, trivalent flu vaccines are manufactured with adjuvants. A well-known example is “Fluad trivalent”. An adjuvant is an ingredient that helps to promote a better and strong immune response. Adjuvants can also reduce the amount of virus needed for the production of a vaccine. Ultimately, this allows greater supplies of manufacturing vaccines.

The only downside observed in this vaccine is hypersensitivity to active ingredients present in the vaccine. The vaccination can be postponed in patients with moderate or severe febrile illness. A high dose of this vaccine is normally recommended for people who are 18 to 65 years. Moreover, trivalent vaccines comply with WHO recommendations and EU decisions.

What is Quadrivalent Flu Vaccine?

Quadrivalent flu vaccine is designed to protect against four different flu viruses, including two influenza A viruses and two influenza B viruses. Quadrivalent flu vaccine usually protects people against four strains of influenza virus: influenza A (H1N1), influenza A (H3N2), Influenza B (B/Washington/02/2019 like strain), and Influenza B (B/Phuket/3073/2013 like strain).

These vaccines are propagated in fertilised eggs of hens from healthy chicken flocks and inactivated with formaldehyde. The vaccine must be given as an intramuscular or subcutaneous injection. This vaccine complies with the WHO recommendations and EU decisions. Adding another influenza B virus to this vaccine aims to give broader protection against circulating flu viruses. There is a quadrivalent flu shot that can be given to children as young as 6 months old. But it is normally recommended for people 3 years and older. The safety and efficacy of quadrivalent vaccines are not tested for infants less than 6 months old. Adjuvanted quadrivalent flu vaccine (Fluad quadrivalent) is an effective alternative type. Most of the flu vaccines in the United State are now quadrivalent. Moreover, 195 million quadrivalent flu vaccine doses are currently available in the US for the 2020-2021 season. Hypersensitivity for active ingredients in the quadrivalent vaccine is a common contradiction.

What are the Similarities Between Trivalent and Quadrivalent Flu Vaccine?

1. Both vaccines are types of flu (Influenza) vaccines.
2. These vaccines reduce the symptoms of seasonal influenza infection.
3. They contain inactivated influenza A and B viruses.
4. They provide protection against influenza A viral strains such as H1N1 and H3N2.
5. They provide protection against influenza B viral strain such as (B/Washington/02/2019 like strain).
6. Both have common contradictions, such as hypersensitivity to active ingredients.

What is the Difference Between Trivalent and Quadrivalent Flu Vaccine?

Trivalent flu vaccine provides protection against three different flu viruses: two influenza A viruses and one influenza B virus. On the other hand, the quadrivalent flu vaccine provides protection against four different flu viruses: two influenza A viruses and two influenza B viruses. This is the key difference between trivalent and quadrivalent flu vaccine. Furthermore, the trivalent flu vaccine is propagated in embryonated chicken eggs. In contrast, the quadrivalent flu vaccine is propagated in fertilised eggs of hens from healthy chicken flocks.

The below infographic presents the differences between trivalent and quadrivalent flu vaccine in tabular form.

Summary – Trivalent vs Quadrivalent

Seasonal influenza has been estimated to cause 3 to 5 million cases of severe illness and approximately 250,000 to 500,000 deaths globally each year. It affects the elderly community, young children and people with specific health conditions largely. Vaccination is the most effective way to prevent influenza infection. Trivalent and quadrivalent flu vaccines are both types of influenza vaccines that contain inactivated form of influenza viruses. The trivalent flu vaccine protects people from three different flu viruses: two influenza A viruses and one influenza B virus. The quadrivalent flu vaccine protects people from four different flu viruses: two influenza A viruses and two influenza B viruses. Thus, this is the summary of the difference between trivalent and quadrivalent flu vaccine.

Reference:

1. Higuera, Valencia. “Types of Flu Shots.” Healthline, Healthline Media.
2. Pasteur, Sanofi “Quadrivalent Influenza Vaccine (Split Virion, Inactivated), Suspension for Injection in Pre-Filled Syringe.” EMC.

Image Courtesy:

1. “INFLUENZA VACCINE: WORLDWIDE INDUSTRIAL NETWORK” By Sanofi Pasteur  (CC BY-NC-ND 2.0) via Flickr
2. “Administering Flu Vaccine” By Government of Prince Edward Island (CC BY-NC-ND 2.0) via Flickr