How Does the Flu Vaccine Work?

How Does the Flu Vaccine Work?

The CDC conducts studies to determine the effectiveness of flu vaccines. Especially when it comes to how well they can protect you against influenza viruses.

You need a flu vaccine every year. Your immune protection from vaccination reduces over time. That’s why you need to get yourself vaccinated for optimal protection. Another reason is that influenza viruses are always changing. Vaccines are actually updated every year. This is to protect you against the viruses that are most common during flu season.

How Does the Flu Vaccine Work?

Are you finally getting your flu vaccine? Wondering “how does the flu vaccine work?” You will find that flu vaccines can cause the antibodies in your body to develop. This will happen about two weeks after you get your vaccine. These antibodies are the ones that provide protection against the infection. 

How well flu vaccines work may differ from season to season. There are two important elements when it comes to “how effective is the flu vaccine” to a person.

  • Characteristics of the person

This is an important factor when it comes to “how does the flu vaccine work.” There are some vaccines that are not recommended for certain groups of people. You see, there are factors that affect your suitability for vaccination. These factors include your age and current and past health. Allergies to flu shots or their components is another factor as well. 

  • How well the vaccines match the flu viruses

It is important that the flu vaccines match the flu viruses spreading in the community. It’s possible that vaccines will provide you little to no protection from illness. That is if the vaccine doesn’t match one or more circulating influenza viruses. Worry not. The vaccine can still provide protection against other flu viruses during the season.

Still, it is better that there is a good match between the vaccines and circulating viruses. Since the vaccination gives benefits by preventing complications and flu illness.How Long Does it Take for the Flu Vaccine to Work?

How Long Does it Take for the Flu Vaccine to Work | Well Health Works

Take note that the flu vaccine doesn’t work right away. According to the CDC, the vaccine takes around two weeks after vaccination to work. After two weeks, the antibodies in your body will be able to provide protection against the virus. 

Wondering how long does the flu vaccine last? The flu vaccine provides protection against the influenza virus for around six months. That’s why you should get a flu shot every year.

For elderlies, aged 65 years and over, the effects of the flu shot wear off earlier. You see, as you get older, your immune response to vaccines weakens. As such, older people are at higher risk than younger people. 

What is in a Flu Vaccine?

It is important that you get vaccinated with the flu vaccine. Especially if you’re among the people who’re at risk of developing flu complications. As such, everyone who is six months of age and older should get the flu vaccine every season.

What is in a flu vaccine? A flu vaccine contains several ingredients. These include:

  • Influenza Viruses

Flu shots actually contain small amounts of inactivated influenza viruses. That might sound worrying but you have no need to worry. That’s because these viruses are dead, meaning they cannot cause the flu.

The nasal spray, in contrast, has live viruses. But these viruses are already weakened so they cannot cause the flu as well.

Are these inactive viruses important? Yes, since they trigger your immune system. Your body’s natural defense mechanism produces antibodies to fight the influenza viruses.

  • Egg Protein

The inactivated viruses are actually grown inside fertilized chicken eggs. That’s because protein helps the viruses grow. The manufacturers, then, separate the virus from the egg. After that, they include it in the flu vaccine. This means that the flu vaccine contains a tiny amount of egg protein.

  • Thimerosal

Manufacturers add thimerosal, a preservative, to multi-dose vaccine vials. There’s a reason why they have to add thimerosal. It can help prevent and kill bacteria and fungi in the vial.

  • Stabilizers

Vaccines need to be stable so they won’t lose potency. As such, manufacturers use sucrose, sorbitol, and monosodium glutamate (MSG). They will be able to keep the vaccines stable. This means that the vaccines will remain potent even when exposed to heat and light.

  • Antibiotics

Vaccine manufacturers add antibiotics in small amounts. Among these antibiotics are neomycin and gentamicin. Antibiotics can stop bacteria from contaminating the vaccines.

  • Polysorbate 80

Polysorbate 80 is an emulsifier added to the flu vaccine in small amounts. It can keep all ingredients in the vaccine distributed in equal amounts.

  • Formaldehyde

Most formaldehyde used in the production undergoes removal from the vaccine solution. This is according to the CDC. Manufacturers conduct this process before they pack the vaccines. After that, they send the vaccines to the doctors and pharmacies. The FDA also confirmed that the level of formaldehyde that remained in the vaccine is low. It’s actually lower than the amount you have in your body. 

Side Effects of the Flu Vaccine

Thinking about the side effects you might experience after receiving the flu shot? The following are the reported mild symptoms of the flu shot:

  • Fever
  • Fatigue
  • Headache
  • Redness, and swelling of the skin around the injection site

Serious side effects include:

  • Swelling of the eyes or lips
  • Hives
  • Trouble breathing or wheezing
  • Fast heartbeat
  • Dizziness
  • Weakness

Do you need onsite health and wellness solutions? At Well Health Works, we provide valuable information and lifestyle education. So you can build awareness of your health risks. Give us a call at 833-935-9355 to know more about our services. You can send in your email at and we’ll answer any questions you have. We will help you create a wellness program for a healthy workplace.

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