Parents who are reluctant to let their children get vaccinated are often hesitant because they have questions about the safety, necessity, and effectiveness of vaccines. We asked experts to address some common concerns.
Parents who are reluctant to have their child vaccinated are often hesitant because they have questions about the safety, necessity, and effectiveness of vaccines. We asked experts to address some common concerns.
Why do vaccines contain chemicals? Are they dangerous?
“Generally speaking, the chemicals in vaccines are necessary preservatives,” says Marie-Ève Brouillette, a perinatal nurse. Other ingredients, called adjuvants, are used to make vaccines more effective. Adjuvants cause inflammation, which serves to activate our immune system. Studies have shown that if there is no adjuvant, the body’s immune response isn’t as strong, says Dr. Arnaud Gagneur, a physician and researcher at the Université de Sherbrooke.
“The ingredients list on its own can be scary,” says Brouillette, “but you have to consider the quantities.” Certain vaccine ingredients are present in much lower concentrations than what’s found in household cleaning products, or even in food. For example, many people are concerned about the aluminum in vaccines. And yet, many foods contain trace amounts of aluminum, including fruits, vegetables, flour, cereal, nuts, dairy products, infant formula, and honey.
How do vaccines work?
Vaccines activate the immune system so the body can defend itself against certain viruses and bacteria. The immune system reacts to molecules called antigens that are found on the surface of viruses and bacteria. When your body encounters an antigen for the first time, explains Dr. Gagneur, it starts to produce antibodies that help fight the disease. This way, if a person encounters the same virus or bacteria again later in life, their antibodies will prevent them from getting sick. “The principle of vaccination is to inject only the antigens, not the parts that could cause the disease,” says Dr. Gagneur. This is sufficient to allow the body to defend itself.
Messenger RNA vaccines, however, such as the COVID-19 vaccines developed by Pfizer and Moderna, are slightly different. Instead of containing antigens, they hold the recipe that allows the body to manufacture its own antigens to trigger an immune response.
While most vaccines contain only parts of inactive bacteria or viruses, there are a few exceptions. Some contain live, weakened bacteria or viruses that have been treated in a laboratory to prevent them from causing disease. This is true of the measles and chickenpox vaccines, for example. Because these vaccines are live, they occasionally cause mild symptoms. For example, a child may get a few spots of chickenpox after receiving the vaccine. However, they won’t be contagious, and they’ll be protected from serious chickenpox complications.
Why vaccinate children against COVID-19 when they’re largely unaffected by the disease?
Children aged 5 and older can’t get the COVID-19 vaccine yet, but this could change by the end of 2021.
According to experts, to achieve herd immunity (i.e., for everyone to be protected against COVID-19), at least 80 percent of the population must be vaccinated. It’s difficult to meet that threshold without vaccinating children, who represent 20 percent of the population.
Even if children don’t develop severe symptoms, they can still transmit the virus. The more the virus is transmitted, the more likely it is to make “mistakes” when replicating itself. These mistakes are the reason why variants arise. Ultimately, the sooner we vaccinate as many people as possible, including children, the fewer new variants we will see.
In addition, kids who contract COVID-19 can, in some cases, develop long COVID or multisystem inflammatory syndrome (link in French).
Why do people need to be vaccinated against diseases that have almost disappeared?
“When we no longer feel threatened by a certain disease, that’s an indication that we’ve done our job with vaccines because large outbreaks have stopped occurring,” says Brouillette. “That said, these diseases are still a threat. That’s why we have to keep vaccinating.” Many diseases that have disappeared in Quebec are still common elsewhere in the world. “The recent measles outbreaks, for example, happened because people who hadn’t been vaccinated caught the disease while travelling,” says Marilou Kiely, a scientific advisor at the INSPQ.
We can only stop vaccinating against a disease once it has been completely eradicated from the planet. This is the case of the virus responsible for smallpox, for instance.
Is a 2-month-old baby too young to receive a vaccine?
“This question is understandable since parents typically think of their baby as being very fragile,” says Brouillette. “However, it’s precisely because babies are fragile that they need to be vaccinated. We have to protect them from diseases that could cause serious harm.”
A baby’s immune system is functional, but not fully mature. It isn’t capable of recognizing certain bacteria, says Dr. Gagneur. “That’s why infants under 2 months are vulnerable to a number of serious infections, like meningitis,” he says. Fortunately, there are vaccines that allow a baby’s immune system to react properly to these bacteria. Delaying vaccination therefore puts babies at greater risk.
Why do I need to have my child vaccinated if most people have already received the vaccine?
The more people are vaccinated, the less likely the disease is to spread. This reduces the risk of infection. “When you vaccinate your child, you’re not just protecting them, you’re also protecting other people’s kids,” adds historian Laurence Monnais, who specializes in the history of health and medicine. “When they’re protected, we’re protected too.” Furthermore, having your child vaccinated helps protect more vulnerable segments of the population who either can’t get vaccinated or are likely not to respond as well to vaccines.
Why isn’t the vaccination schedule more spaced out?
“Parents can choose whether or not to vaccinate their child and whether to follow the applicable vaccination schedule,” says Brouillette. “But this can have an effect on the level of protection their child will benefit from.”
As Kiely notes, the vaccination schedule was designed in accordance with the risk associated with certain diseases and the strength of a child’s immune system: “Early doses are effective in preventing complications. However, to ensure adequate protection, several doses are required before the age of 2. Delaying vaccination makes a child more vulnerable. That’s why it’s best to follow the schedule, which was developed by experts.”
Vaccine hesitancy isn’t the same as being anti-vaccine. Rather, it’s a sign that many parents have questions about vaccines.
Parents appreciate having their vaccine questions answered without judgment.
Vaccines help protect children against certain diseases or at least prevent serious complications.
Source:Naître et grandir magazine, September–October 2021
Research and copywriting: Kathleen Couillard
Scientific review: Ève Dubé, medical anthropologist at the INSPQ; and Dr. Caroline Quach, pediatrician and microbiologist/infectious disease specialist at CHU Sainte-Justine and full professor at the Université de Montréal
“Demystifying beliefs regarding the risks of vaccination.”
Gouvernement du Québec.
- Étude sur la couverture vaccinale des enfants québécois âgés de 1 an, 2 ans et 7 ans en 2019. Kiely, Marilou, et al. Institut national de santé publique du Québec, 2021.
“L’hésitation à la vaccination.” Dubé, Ève. Institut national de santé publique du Québec, 2017.
- Le mythe du refus, L. Monnais, Presse de l’Université de Montréal, 2019, 288 p.
Common questions about vaccines (French only).
Photos (in order): GettyImages/Geber86, GettyImages/Rawpixel, GettyImages/Solstock, and GettyImages/Fluxfactory