National Immunization Day: see 6 myths about vaccines that are still alive

Vaccines are considered one of the greatest advances in medicine, being responsible for drastically reducing serious diseases and saving millions of lives every year. However, they still face two challenges: misinformation and distrust on the part of the population.

Even after decades of scientific studies and public health campaigns, myths about immunization continue to circulate on social media and in message groups. False information that can compromise vaccination coverage and favor the return of previously controlled diseases.

See below six myths about vaccines that continue to survive and what experts say about them.

"Vaccines cause autism"
This is one of the best-known myths and also one of the most debunked by science. The false relationship emerged after the publication of a study in 1998, later withdrawn from the scientific community due to fraud and serious errors in research.

Since then, dozens of studies carried out in different countries have followed millions of children and found no link between vaccines and autism. Organizations such as the World Health Organization and the Centers for Disease Control and Prevention reinforce that vaccines are safe and do not cause autism spectrum disorder.

"This issue of autism is related to a study published many years ago and that anti-vaccine groups take advantage of, despite it having been retracted, having already been denied, and having already been demonstrated several times that it is not true", explains Alberto Chebabo, infectious disease specialist at Dasa's Bronstein laboratory.

"It is better to catch the disease than to get vaccinated"
Although some diseases can generate natural immunity, the risks associated with infection are often much greater than the possible side effects of vaccines.

Measles, meningitis and covid-19, for example, can cause serious complications, permanent sequelae and even death. Vaccines stimulate the immune system in a controlled way, significantly reducing the chances of serious cases.

According to experts, immunization is precisely a way to prevent the body from facing the real dangers of the disease.

"Vaccine development techniques will stimulate this immune system to develop protective mechanisms against that agent. Natural infection will cause an infection that is often serious, with risks, including death. So, waiting for natural immunity to occur, increases the risk of complications and increases mortality", adds Chebabo.

"Vaccines weaken the immune system"
The immune system is prepared to deal with thousands of viruses and bacteria on a daily basis. Vaccines use a small fraction of these agents, inactivated or weakened, to teach the body how to defend itself.

In practice, they strengthen the immune response by creating memory against specific diseases. Studies show that vaccinated children and adults are not more vulnerable to infections because of vaccines.

Experts also state that the number of antigens present in current vaccines is much lower than the natural contact that the body has with microorganisms on a daily basis.

"Flu vaccine causes flu"
It is probably the most repeated fake news every year. But the explanation is simple: the flu vaccines used in Brazil use inactivated viruses or just viral fragments, that is, they cannot cause the disease.

What some people feel after receiving the dose are expected signs of the immune response to vaccination, such as pain in the arm, mild tiredness or a low-grade fever for a short period.

In Brazil, the SUS flu vaccination campaign uses the trivalent vaccine, which protects against three strains of the virus and is aimed at priority groups defined by the Ministry of Health, such as the elderly, children, pregnant women, postpartum women, health professionals and people with comorbidities.

"The vaccine does not cause flu because it does not contain a virus capable of replicating itself. Often, the person was already incubating another respiratory virus or interprets a mild reaction as illness, which often generates confusion at this time of year", says Maria Isabel de Moraes-Pinto, infectious disease specialist at Delboni, in São Paulo, and vaccines coordinator at Dasa.

"Vaccines contain dangerous substances"
Another recurring myth involves the components used in the manufacture of vaccines. Preservatives and stabilizers are often identified as toxic, despite being present in safe and strictly controlled quantities.

Regulatory agencies such as Anvisa evaluate the ingredients of all vaccines before release for use. Furthermore, immunizers undergo clinical testing and continuous monitoring after reaching the population.

Serious adverse reactions are rare and generally much less dangerous than complications caused by the diseases vaccines prevent.

"As some diseases have disappeared, it is no longer necessary to vaccinate"
The reduction in diseases such as polio and measles occurred precisely thanks to mass vaccination campaigns. When vaccination coverage drops, the risk of reintroduction of these diseases increases.

This is what happened in several countries in recent years, with new measles outbreaks following a drop in immunization rates. Experts warn that viruses and bacteria continue to circulate in different regions of the world, which makes vaccination essential.

Collective protection depends on high immunization rates. The more people vaccinated, the lower the circulation of infectious agents and the greater the protection of vulnerable groups, such as the elderly, babies and immunosuppressed people.

Fighting misinformation
Health authorities argue that combating fake news is a fundamental part of vaccination strategies. The recommendation is to seek information from reliable sources, such as official bodies, medical societies and health professionals.

For experts, vaccination remains one of the most effective measures to prevent disease, reduce hospitalizations and avoid deaths.

"One of the biggest problems we have is exactly the issue of misinformation about vaccines. All immunizers undergo important safety and efficacy studies. This fake news uses false information. Sometimes, they are mixed with partially true information to give a truthful character, and discourage people from getting vaccinated. This leads to a decline and distrust of vaccination, causing a risk of complications and the reintroduction of some diseases", says Chebabo.

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Source: CNN