Common questions about vaccine safety

Are vaccines safe?

The vaccines your child receives when you bring him or her to be immunized here in Alberta, are safe. These vaccines protect your child from diseases that are definitely not safe.

By getting your child immunized, you’re giving your child the opportunity to build natural immunity to – or “armour” against – disease, before he or she is actually exposed to these diseases. Allowing your child to be exposed to these diseases without being immunized (or “unarmed”) is not a safe alternative to immunization.

These diseases put your child at risk of experiencing such severe health issues as hearing loss, paralysis, and brain and/or heart damage. And the risk of these severe health issues is greater than the risk of your child experiencing a reaction after immunization. 

Severe allergic reactions to immunizations occur at a rate of approximately only one for every one million doses of vaccine distributed in Canada, each year. 

The most common symptoms children experience after immunization are temporary redness, swelling or pain where the needle has been given. These symptoms usually pass one to three days after immunization. 

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How is vaccine safety monitored in Canada?

In Canada, the process of manufacturing vaccines is lengthy and carefully supervised by Health Canada.

On average, 10 years of research and studied development take place before a vaccine will even be considered for approval in Canada.

Health Canada requires extensive and scientific and clinical evidence demonstrating the safety and value of the vaccine before it will consider the vaccine for use in Canada.

And, once a vaccine is approved, Health Canada continues to regulate vaccine production, requiring every single vaccine batch to be tested for safety and quality before distribution.

The nurse immunizing your child is also required to follow strict policies and guidelines, to ensure the immunization is given safely, effectively, and with your consent and understanding. 

Your child’s safety is at the heart of immunization, from manufacturing to monitoring to administration.

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Are the risks of the vaccine worse than the risks of the disease?

No. In fact, the risks that diseases pose to your child are far greater and more severe than risks associated with immunizations.

Diseases put your child at risk of experiencing such severe health issues as hearing loss, paralysis, and brain and/or heart damage. And the risk of these severe health issues is greater than the risk of your child experiencing a reaction after immunization. 

Severe allergic reactions to immunizations occur at a rate of approximately only one for every one million doses of vaccine distributed in Canada, each year. 

The most common symptoms children experience after immunization are temporary redness, swelling or pain where the needle has been given. These symptoms usually pass one to three days after immunization. 

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Will the vaccine/immunization give my child the disease it's supposed to prevent?

No – your child cannot get the disease from the vaccine, or from being immunized.  Most vaccines do not contain any live virus at all. And, the vaccines that do contain very tiny amounts of “live” virus are manufactured so that the virus is able to prompt your child’s natural immune response, but is not able to make your child get sick. 

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Do vaccines overwhelm the immune system?

Actually, quite the opposite! By prompting the immune system to do what it is naturally meant to do – develop antibodies that can fight disease and keep your child healthy – vaccines make your child’s immune system even stronger! It is natural for your child to be exposed to many different forms of bacteria and viruses every day, whether it be through eating, playing with others, touching their mouths, or even just crawling on the ground. By comparison, the minute amount of a weakened or killed form of a virus or bacteria that is contained in vaccines is controlled to ensure that your child gets just enough to prompt his or her immune system to respond as it is supposed to, without getting sick. The prompt causes your child’s body to naturally make what are called “antibodies.” These antibodies will recognize and attack disease-causing virus or bacteria, should your child be exposed to it again after being immunized.

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Does having multiple shots at one appointment put my child’s immune system at risk?

No, multiple immunization shots will not compromise or overwhelm your child’s immune system. In fact, research has confirmed that giving your child several routine immunizations at one appointment does not increase the risk of reaction at all. Only vaccines shown to be safe and effective when given together are given at the same time. Research has also shown that having your child immunized with multiple injections at one visit will also actually cause less pain than waiting a few days between each vaccine.

Remember: It is natural for your child to be exposed to many different forms of bacteria and viruses every day, whether through eating, playing with others, touching their mouths, or even just crawling on the ground. By comparison, the very tiny amount of a weakened or killed form of a virus or bacteria that is contained in a vaccine is just enough to prompt your child’s immune system to respond and build antibodies, without causing your child to actually get sick. These antibodies will recognize and attack disease-causing virus or bacteria, should your child be exposed to it again after being immunized. 

Giving your child all of the vaccines at the age recommended does ensure your child’s health is best protected.

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How many vaccines can my baby safely have at one time?

It is safe for your baby to receive all the vaccines recommended in the routine childhood immunization schedule, at each appointment time. Research has confirmed that giving your baby the recommended several routine immunizations at one appointment does not increase the risk of reaction at all. Only vaccines shown to be safe and effective when given together are given at the same time. Research has also shown that having your baby immunized with multiple injections at one visit will also actually cause less pain than waiting a few days between each vaccine.

Remember: It is natural for your baby to be exposed to many different forms of bacteria and viruses every day, whether through eating, playing with others, touching their mouths, or even just crawling on the ground. By comparison, the very tiny amount of a weakened or killed form of a virus or bacteria that is contained in a vaccine is just enough to prompt your baby’s immune system to respond and build antibodies, without causing your baby to actually get sick. These antibodies will recognize and attack disease-causing virus or bacteria, should your child be exposed to it again after being immunized. 

Giving your child all of the vaccines at the age recommended does ensure your baby’s health is best protected.

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Can vaccines/immunization cause seizures?

There are many causes of seizures in children including infections, head trauma and lack of oxygen, and rarely, immunization. 50% of seizures in children are what are called “febrile seizures.” Febrile seizures are most often caused by infections: 200 to 500 children out of 10,000 children will have a febrile seizure by the age of five. By comparison, only eight out of 10,000 children will have a febrile seizure after receiving the MMR vaccine. So, the risk of febrile seizure after immunization is much lower than the risk all children have of experiencing a febrile seizure in childhood.

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Do vaccines cause autism?

No, vaccines do not cause autism. Research has found no links between vaccine and autism.

You may have heard about Andrew Wakefield, a British surgeon who suggested a link between autism and vaccine. What you may not have heard is that the research he published was found to be false, and Wakefield had his medical licence taken away because of this. In January 2010, Britain’s statutory tribunal of the General Medical Council found Wakefield guilty of four counts of dishonesty and 12 counts involving the abuse of developmentally challenged children, as it pertained to his false research on autism.

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Do vaccines/immunizations cause allergies?

A number of studies have been completed on this question, and found no evidence that vaccines cause allergies. Further research into this question is still being done; however, we already know that the benefits of immunization greatly outweigh the risk of developing an allergy.

It is important to talk to your healthcare provider about any allergies you or your children may have, before your child is immunized. Your healthcare provider will recommend what is safe for your child, based on his or her medical history, including allergies.

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My child has allergies – how do I know if immunization is safe?

At your child’s immunization appointment, your nurse will talk to you about your child’s health history before giving your child any immunization. This will include questions about any medicines your child is taking, health conditions your child has or is experiencing, as well as any allergies your child may have. When your nurse talks to you about your child’s health history, it is important that you inform your nurse of any and all of your child’s allergies before your child receives any vaccines. Your nurse will guide you on what is safe for your child, based on your child’s health history, including any allergies your child may have.

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If my child is allergic to eggs, can my child be immunized?

Several vaccines we use in Alberta are created using manufacturing processes that involve hens’ eggs or related elements. This process may result in the some vaccines containing trace amounts of egg and chicken protein, including the measles-mumps-rubella (MMR) vaccine, the measles-mumps-rubella-varicella (MMRV) vaccine, and influenza vaccines.

Vaccines that contain small quantities of egg protein can cause hypersensitivity reactions in some people with allergies to eggs.While it is rare that your child would experience a severe reaction after receiving these types of vaccine, it is important that you discuss this with your healthcare provider or immunizing nurse, before your child receives any vaccine.

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Is there formaldehyde in vaccines? Why?

Formaldehyde is used early in the manufacturing process of some vaccines to make viruses and toxins harmless. The formaldehyde is then removed during the rest of the manufacturing process, leaving at maximum only trace amounts in the vaccine. By comparison, an infant’s body naturally contains about ten times more formaldehyde at any time than there is in a vaccine.

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Is there aluminum in vaccines? Why?

Aluminum salts may be added to a vaccine to prompt your child to have a stronger natural immune response to immunization. The amount of aluminum present in vaccine is similar to the amount of aluminum naturally present in breast milk and infant formula.

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Is there thimerosal or mercury in vaccines? Why?

Routine childhood immunizations (in Canada) do not contain thimerosal, with the exception of certain influenza vaccines.

Thimerosal is a preservative. Preservatives play an important role in enhancing vaccine safety, as preservatives prevent the growth of germs, bacteria and fungi that can contaminate vaccine.

Mercury is not added to vaccines. Thimerosal – the preservative that is present only in some influenza vaccines – contains a minute amount of one form of mercury. That form of mercury does not accumulate (or build up) in a person’s body.

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Do some vaccines contain cells from aborted fetuses? Which ones and why?

Vaccines do not contain cells from aborted fetuses or other human cells. Human cell lines may be used in the early stages of production of some vaccines; however, all cells are removed during the vaccine manufacturing process.

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