Flu (influenza) season is quickly approaching in the United States. 

Per the CDC’s recommendation, all individuals aged six-months and older should receive a flu vaccine each year – ideally in October – to protect themselves (and others) against the flu. 

However, there are multiple types of flu vaccines to choose from depending on your age, health conditions, and personal preferences. In this article, we are going to explain these differences so you can explore which vaccine type is right for you.  

 

Different Types of Flu Vaccines

There are two categories of influenza vaccines: trivalent, which protects against three strains of the virus (two A strains and one B strain), and quadrivalent, which protects against four strains (two A strains and two B strains). 

Within these two categories, there are numerous vaccine types to accommodate individuals of varying ages and health conditions so everyone can protect themselves (and others) against the flu. 

Trivalent Flu Vaccines

There are two types of trivalent flu vaccines to choose from: regular dose and high dose. 

• Regular-dose trivalent is the most common type of flu vaccine. It is grown within an egg and administered via a needle (or “shot”). This vaccine type is only available to individuals aged 18 to 64 years old. 
• High-dose trivalent (also known as Fluad Trivalent) is only approved for individuals aged 65 and up. This vaccine type is also grown within an egg. It contains four times the amount of antigen as the regular dose in order to give the older population added protection against the flu virus. 

 

Quadrivalent Flu Vaccines

Quadrivalent vaccines, which protect against four strains of influenza, are much more accommodating than trivalent vaccines. There are six types to choose from. 

• Regular-dose quadrivalent, unlike regular-dose trivalent, comes in two forms: the common egg-grown version and an alternative version grown in a cell culture. 

The egg-grown version of regular-dose quadrivalent is approved for children aged six-months and older (much lower than the 18+ requirement for trivalent). 

There is also an adjuvanted option (called FLUAD Quadrivalent) for individuals aged 65 and up. Adjuvant is an ingredient added to a vaccine to promote a stronger immune response without the need for a higher dose. 

The cell-grown version of the regular-dose quadrivalent is approved for children ages four and up. It is ideal for those with egg allergies or who are opposed to the use of animal-derived products. 

There is another egg-free alternative called a “recombinant” vaccine, which we will discuss below.

• High-dose quadrivalent (also known as Fluzone) is very similar to its trivalent alternative. Both are intended for individuals aged 65 and up; the only difference is the number of strains they protect against (four versus three). 

As mentioned above, an alternative to high-dose quadrivalent is a regular-dose, adjuvanted quadrivalent (such as FLUAD). 

• Unlike trivalent, quadrivalent has a needle-free option called AFLURIA Quadrivalent®, which uses a jet injector to administer the flu vaccine. 

A jet injector works by sending a high-pressure stream of fluid through the skin and into the bloodstream, making it a great option for those with trypanophobia (fear of needles). However, it is only approved for ages 18-64. 

AFLURIA also comes in a non-jet form if you prefer a traditional shot.

• Recombinant quadrivalent is a synthetic form of the flu vaccine which does not require the use of egg-grown methods. There is only one recombinant form of the quadrivalent flu shot (known as Flublok) available for the 2021/22 flu season. 

Recombinant and cell-culture quadrivalent are ideal for vegans and those with egg allergies. The main difference is that the recombinant Flublok vaccine is approved for people aged 18 and up while the cell-culture version is approved for ages four and up.  

• Intranasal spray is the last type of quadrivalent flu vaccine. 

All of the vaccines we have discussed up to this point have been “inactivated,” meaning they do not contain a live sample of the influenza virus. 

However, the nasal spray vaccine is classified as “live attenuated,” meaning it contains a weakened form of the virus. Because of this, it is only approved for healthy, non-pregnant people between the ages of 2 and 49.  

Intranasal spray, like the jet injector, is an alternative to traditional needle-administered flu vaccines. However, there are numerous requirements you must meet in order to be approved for intranasal spray.

You can find a full list of these requirements here.

 

Ready to receive your flu vaccine for the 2021/22 season?

Community Pharmacy offers a variety of flu vaccine options to accommodate a wide range of individuals. No matter your age, health status, or philosophical beliefs, we can help you find a flu vaccine that meets your needs. 

This season, we are offering:

• Two versions of the regular dose, egg-grown quadrivalent (Fluzone and Afluria)
• The high-dose, egg-grown quadrivalent (Fluzone HD)
• The regular-dose, adjuvanted quadrivalent (Fluad)

To schedule your flu shot with Community Pharmacy, visit our website here.

 

Common Questions Related to the Flu Vaccine

How are flu vaccines made?

Flu vaccines can be made in one of three ways: an egg-based manufacturing process, a cell-based production process, or a synthetic (recombinant) process. For more information on the differences among these three options, visit the CDC’s website here.

 

Is one flu vaccine type better than another?

The type of flu vaccine you need depends on your age, health condition, and personal preferences. Aside from these factors, the CDC does not advocate one vaccine type over another. 

To find out which vaccine type is right for you, consult your doctor or healthcare professional. 

Are flu vaccines effective?

Yes. The effectiveness of flu vaccines varies with each season due to the ever-changing nature of the virus. However, receiving a flu vaccine significantly reduces your chance of becoming sick from the flu and spreading the virus to others; it also lessens the severity of the virus if you do become sick. 

 

Why are some vaccines only for people aged 65 and older?

According to CDC research, people 65 years and older account for 70-85% of flu-related deaths – and 50-70% of flu-related hospitalizations – each flu season. Part of the reason is that older individuals typically have lower immune responses to vaccines than younger people, thereby making them more vulnerable to influenza. 

High-dose and adjuvanted vaccines are designed to help create stronger immune responses in the older population, therefore increasing their protection against the flu. 

 

For more information on the effectiveness of flu vaccines, visit the CDC’s website here.

 

About Community Pharmacy

Community Pharmacy is a locally and family owned pharmacy that has been serving Texas since 1982. With locations in Denton, Corinth, Lewisville, and Flower Mound, we strive to provide an effortless pharmacy experience that patients can look forward to. Our caring and knowledgeable staff is committed to providing the highest quality service with integrity and compassion to meet the needs of those we serve.