Baby health

Worried about vaccines? Your top questions answered

Caught up in the debate of vaccinations? Dr. Joelene Huber gives you the expert advice you need to know.

Photo: iStockphoto Photo: iStockphoto

There’s been a lot of talk about vaccination rates that's left some parents wondering—"Are vaccines safe?" Angry fingers are being pointed back and forth across the pro and anti-vaccination divide. We reached out to Joelene Huber, a pediatrician at St. Michael’s Hospital and the Hospital for Sick Children in Toronto and an assistant professor in Pediatrics at the University of Toronto, to address some common concerns about vaccines.

Why does it matter to a parent who’s chosen to vaccinate if I don’t vaccinate my child? If they’ve received the immunization, shouldn’t they be protected? Many parents view communicable diseases as a community or public health issue, especially when there is a threat of an outbreak. This is because a small percentage of vaccinated children can still contract the diseases or milder forms of the diseases they’re vaccinated for if they come in contact with a person who is contagious. Further, many parents who have a fully vaccinated child also have a younger child or baby who is not fully immunized that they’re often worried about. In order to understand this perspective, it’s important to understand the concept of “community” immunity (also known as “herd” immunity).

Community immunity refers to the fact that if the majority of the community is immunized (ideally around 95%), those who are not vaccinated are still likely to be protected. This is due to the fact that if a non-immunized person does acquire a contagious disease (like getting measles while on vacation abroad), the spread of infectious disease can be contained when they return home if most members of the community that person comes into contact with while he/she is contagious are immunized. Community immunity is particularly important for protecting the most vulnerable, non-immunized members of the community, such as: babies who aren’t old enough to be immunized; premature babies who are susceptible to infections; toddlers, preschoolers, and younger siblings who aren’t fully immunized (i.e., need a booster shot prior to entering school); babies and children with cancer whose immune systems are compromised or are undergoing cancer treatments; babies and children who have undergone an organ transplant and can’t be immunized and children of parents who have forgotten to immunize or chosen not to immunize. The risk of depending on community immunity is that if the number of non-immunized people falls too much below the 95% mark, an outbreak could occur and babies and kids who are not immunized are often the most seriously affected.

As a collective whole, we have the potential to be part of helping to prevent illness in others, as well as ourselves, if those who can be immunized are immunized. Together, we can help to protect the most vulnerable members of society who cannot be immunized by guarding them from coming into contact with a contagious and potentially life-threatening diseases.

Pharmaceutical companies make a profit from vaccines, so it’s in their interest to make sure as many kids use their products as possible. Aren’t all doctors in the pocket of Big Pharma? The vast majority of doctors and nurses don’t have any financial relationship with vaccine pharmaceutical companies, and doctors and nurses don’t share in the pharmaceutical profits by immunizing children. Immunization practices are guided by evidence-based research, the Canadian Pediatric Society recommendations, the National Advisory Committee on Immunizations, the Public Health Agency of Canada, and according to the Health Canada regulations.

Aren’t some of these diseases just rashes or a sore throat? Kids get sick, that’s just life. We’re really lucky in Canada that most people today have never seen many of the diseases that we vaccinate for, because they’ve become so rare with the availability of immunizations. However, we often say that these diseases are “only a flight away,” meaning that if a non-immunized child goes on a vacation in an endemic area, or if a visitor comes to Canada with a contagious infectious disease, non-immunized people could be at risk. While some of the diseases we vaccinate for may initially look like a common cold (i.e., measles may initially appear as a “head cold” with a fever, cough, runny nose and red eyes followed by a rash), they can quickly progress to more serious infections with severe complications (such as encephalitis, which is swelling of the brain, a complication of measles that may result in seizures, permanent brain damage, and even death).


Many of the diseases we vaccinate for are extremely contagious and actually killed several hundreds of Canadians per year prior to immunization availability. Many people don’t realize that the illnesses we vaccinate for can have devastating effects. For example, prior to immunization, Mumps was the most common cause of meningitis (swelling and infection of the lining of the brain), and was a common cause of deafness. Mumps can also lead to infertility in adult males. Poliomyelitis (“polio”) is also known as infantile paralysis, because it can cause inflammation of the spinal cord leading to permanent paralysis, even quadriplegia. Tetanus, commonly caused by a puncture or wound infection, causes severe muscle spasms due to a neurotoxin and commonly progresses to more life threatening symptoms.

What percentage of kids have severe reactions to the standard vaccines? Vaccinations are considered one of the safest medical advances of modern medicine. However, they aren’t actually that “modern” anymore. For example, the measles vaccination has been in use for nearly 50 years. We benefit today from the time-tested reputation for safety of vaccinations. Common mild side effects to standard vaccines include tenderness around the injection site, redness and a mild fever. The Public Health Agency of Canada reports that serious side effects occur in less than 1 person for every million vaccination doses administered, that’s 0.000001%. Further, they note that no long-term effects have been associated with any of the current vaccinations in use in Canada. As the Canadian Pediatric Society reports, it’s more likely that an unimmunized child will get a vaccine-preventable disease than the very rare risk of having an adverse side effect.

We are told to introduce new foods to our babies one at a time to rule out allergies. Why wouldn’t we do the same with vaccines? Vaccinations are the introduction of a very small and modified substance that generates an immune response so that the person builds immunity to that disease. Some vaccinations are given over a series of several small doses as this helps to build immunity. Some parents ask if they can separate combination vaccinations (i.e., vaccinations that immunize against more than one disease at a time). This is discouraged for a number of reasons. Many studies have shown that giving combinations of certain vaccines is both effective and safe. This has enabled infants to be effectively immunized sooner against potentially acquiring a contagious disease, decreases the number of times a baby is poked by needles, and decreases the number of times a baby has to visit the doctor’s waiting room, potentially among others with contagious illnesses.

I get that vaccines have been proven not to cause autism, but then how do you explain the rises in autism, diabetes, asthma, allergies and childhood cancers? Childhood diseases such as diabetes, cancer, asthma and autism spectrum disorders all have distinct symptoms with very different underlying processes. There are no known childhood diseases caused by vaccinations. Research has shown that vaccinations don’t increase the rate of allergies, asthma, Sudden Infant Death Syndrome or autism spectrum disorders. Many of the vaccinations, such as the measles vaccination, have been in wide use for almost 50 years and therefore are unlikely to explain a recent rise in a particular childhood disorder. While some childhood disorders are on the rise (the Centre for Disease Control recently released new data indicating that Autism spectrum disorders occur in 1 in 68 children, a 30 percent rise since the last report in 2012), there have not been major changes in vaccination rates during this time that could account for this.

Why do we give kids so many more vaccines than we ourselves got? This is primarily due to the availability of new vaccines that weren’t available when many parents were younger. For example, we now have vaccinations to help prevent meningococcal meningitis (swelling and infection of the lining of the brain) and meningococcal blood infections. Other newer vaccines include Gardasil, which helps prevent certain strains of human papillomavirus that cause cervical cancers as well as some vaginal, penile and anal cancers and genital warts.


How much testing do Canadian vaccines undergo? Vaccinations used in Canada undergo rigorous testing before being approved for use. Further, the safety of vaccinations is continuously being monitored and tested in Canada and in other countries around the world. Health Canada inspects and supervises all stages of vaccine production in order to uphold a very high level of safety, and guidelines require safety and quality testing of all batches of vaccinations prior to release from the vaccine manufacturer. This testing is regularly completed by both the manufacturer and a Health Canada laboratory. There’s also a surveillance system in place for adverse reactions (Canadian Adverse Events Following Immunization Surveillance System) as well as IMPACT, Canada’s Immunization Monitoring Program ACTive, a pediatric hospital-based national surveillance network.

What chemicals are in vaccines, like mercury, that are potentially harmful to my child? Due to stringent health testing and policies, vaccines don’t contain harmful levels of chemicals. Two commonly discussed preservatives include Thimerosal and formaldehyde.

Thimerosal is a mercury-containing preservative that was used prior to 2001 in some vaccinations in Canada. Although it was considered safe in the small doses previously used in vaccines and has not been shown to cause any adverse health effects, Health Canada instituted a policy in 2001 that no routinely scheduled childhood vaccines could contain Thimerosal. Interestingly, the MMR (measles, mumps and rubella) vaccination (which has been blamed in the past for containing mercury and causing autism) has never contained Thimerosal in Canada.

Formaldehyde, which is a naturally occurring substance in the human body, may be used in the process of producing vaccinations, but is mostly removed through the vaccination purification process. It should be noted that formaldehyde has a role in metabolism and the amount of naturally occurring formaldehyde in an infant is much greater than that of the amount in a vaccination.

I didn’t vaccinate my children when they were babies, but now I’d like to. Is it too late? With the current outbreaks in Canada, many parents of non-immunized children have been seeking vaccination for their child(ren). Even if your children have missed the earlier scheduled immunizations, they can still be vaccinated. Parents are encouraged to talk to their doctor to discuss a catch-up schedule. Waiting until a child is exposed or an outbreak occurs before they’re immunized may not always protect them, however, as many of these infectious diseases are highly contagious (for example, 90% of non-immunized individuals in the same room as a measles carrier will get it) and individuals who have these infections are often contagious before they exhibit symptoms.

This article was originally published on Sep 11, 2015

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