The Difference Between a Vaccine and a Booster Shot


A vaccine is the first and primary means of immunizing you from a sickness or a disease. Some vaccines can last for a certain period of time. After that time, they may lose effectiveness and the body can again be susceptible to the disease from which you have been immunized. Depending on the type of vaccine that you have received, you may need periodic booster shots at some points in your life. In other words, the vaccine is the first shot where you build your immunity and the booster maintains your immunity as the initial resistance weakens.

What a Vaccine Does for Your Body

When a patient receives a vaccine, they are often injected with a form of the virus in order for the body to build immunity to the disease. For example, a live virus attenuated vaccine injects a weakened form of live virus into your body in order to cause a small infection. When your body fights off this minor infection, it builds up a strong immune response that protects you from future infections of that type. Vaccines can also rely on the use of inactivated virus which was previously weakened or killed. In other words, in order to build immunity, you are using the exact thing from which you are being immunized.

While you may have some sort of reaction when you receive a vaccine, you will not get the disease itself. For example, while you may have a small chance of an injury to your arm or an allergic reaction when you get the flu shot, you will not get the flu. You may get flu-like symptoms when you are vaccinated, but you will not develop the disease. This is because the form of the virus that is injected into your body is not the full-strength disease. You will also need to get an annual flu vaccination because the form of influenza that goes around each year is slightly different. Other diseases from which you are vaccinated are the same and the vaccination will also be uniform and only needs to be given once.

Since vaccines are meant to address present or recent dangers, the recommended course of vaccines changes from time to time. For example, decades ago, every child received the smallpox vaccine. Now that the disease has been eradicated, children no longer receive this vaccine.

There is a difference between the protection that you receive from a live virus versus inactivated virus vaccines. The immunity that you will build up from a live virus vaccine is stronger. Inactivated virus vaccine will result in immunity, but it is either not complete protection or the immunity will decline over time.

Inactivated Virus Vaccine Will Require Boosters

Inactivated vaccines may require more than one shot in order for you to build stronger immunity. Live virus vaccines will often only need one shot for a lifetime. The weaker strength of an inactivated virus vaccine means that you will need shots not only immediately after the initial one but also over the course of your lifetime. In addition, vaccines that use a piece of the virus or a specific part of the germ will also need subsequent shots to maintain immunity.

In some cases, the body’s immune system will need an occasional “boost” to keep the antibodies up that the body needs to fight disease. Sometimes, diseases will make a comeback after it was thought that childhood vaccination had significantly reduced the risk of occurrence. Sometimes, there are outbreaks of disease in adults who had already been immunized as children, evidencing the fact that the vaccine is not effective on a lifelong basis after it has already been given once. This shows that some vaccines will need to be periodically boosted over the course of your lifetime.

Sometimes, the booster shot is stimulation that keeps the antibodies established after the initial vaccination alive. Many cells that are developed as a result of the initial booster do not divide or undergo mitosis, so they go into decline some time after the initial vaccine. This is why booster vaccines are needed to periodically foster the growth of new cells that are needed to fight the disease.

Some vaccines can be effective for a lifetime. For example, after you receive a hepatitis vaccine once, you will not need it again over the course of your lifetime. However, the tetanus vaccine is only fully effective for a period of time. As a result, you will need a tetanus booster every ten years. No matter when you had your last booster, you will need one if you have experienced a puncture wound.

Dig a little deeper on Tetanus Vaccine

Possible Side Effects of Boosters

While booster shots are helpful in many instances, they may have some side effects and complications. If the patient already has a high level of antibodies and still receive a booster shot, there is a possibility that the patient can experience a reaction. Recent research has shown that booster shots may be necessarily less frequently than initially thought. For example, a recent study found that tetanus boosters may be needed only once every 30 years as opposed to every ten as previously thought.

Booster shots can also reintroduce some of the risks that are attendant to the initial vaccination. They are injections so if the shot is given in the wrong place, the patient can be at the risk of arm and shoulder injury. Additionally, the patient can also develop an allergic reaction from the contents of the vaccine which can be severe in rare instances. If you or a loved one has been injured from a vaccine, contact The Law Offices of Sadaka Associates today for a free consultation. You may be entitled to compensation through the Vaccine Injury Compensation Program.

Stay Informed

Download Your
Free Vaccine Injury Kit

You will learn about the most common vaccine injuries,
what causes them, and how Sadaka Law can help you.


Founded by Mark T. Sadaka, Esq., Sadaka Law is a premier law firm experienced in handling complex lawsuits for injured people throughout the country. Find out if you have a case.


You Only Have Three Years To File Your Claim

The first step in helping yourself or a loved one after a serious vaccine related injury is to contact us for a free review of your case.

We want to
hear your story.

START getting your life back

Recent Posts