As a mother I have always wanted to protect my daughters from illnesses, that’s why they both have all the mandatory vaccinations and also any other extra vaccine their pediatrician considers necessary. I firmly believe vaccines are the most importante medical breakthrough in modern times and that they have, singlehandedly saved more lives than any other way of prevention and treatment of disease.

Like every mother I suffered liked crazy with my girls’ first vaccines, I cried more than they did. But even after this, I brought them back two months later for their next set of vaccines. And I’ve done the same thing every time I’ve had to. And I will keep on doing it until they are fully immunized.

Why am I telling you this? Because for a while now there has been a growing amount of anti- vaccine movements all over the world. They spend their time badmouthing and spreading lies and disinformation about vaccines. These anti-vaccine groups fill people’s heads with half truths, lies and fabrications about alleged side effects of vaccines. They prey on new parents´ fear to tell made up stories about what will happen to their children if they dare vaccinate them. 

As the mother of a child with autism and a healthcare professional I feel obligated to expose the truth and explain what is behind these allegations and false information going around about vaccines.

The Wakefield fraud

In February 1998 Andrew Wakefield, a British gastroenterologist, published in the prestigious medical journal The Lancet a study that links the MMR (measles, mumps and rubella) vaccine with autism. As expected, panic spread and many parents stopped giving vaccines to their children, not only the MMR vaccine implicated in the study, but all vaccines were treated as potentially dangerous. This took the vaccination rate un the UK form 92% in 1997 plummeting to an 83% in 2002. This drop could help the reappearance of epidemic outbreaks of measles and mumps, as well as elevate the incidence of congenital rubella. These risks apply to every place where the vaccination rate is lower than the minimum needed to maintain collective immunity.

After its publication, other investigators were unable to replicate the results or confirm the hypothesis presented in the study about any kind of relation between exposure to the MMR vaccine and autism. 

In 2004, reporter Brian Deer found information about a serious conflict of interest that Wakefield had in relation to the study. The British Medical Journal published a series of reports about inquiries about the MMR vaccine study and the irregularities that surrounded it. Fiona Goode, the article editor, indicated that, of the 12 children who participated in the study, five showed developmental disorders prior to receiving the vaccine and three never had autism.

According to these investigations, Andrew Wakefield received money form a group of lawyers who were trying to put together a lawsuit against the pharmaceutical manufacturer of the MMR vaccine. This is considered a serious conflict of interest that Wakefield neglected to share with his fellow participants in the study or people from The Lancet who published the study.

In 2004, after the irregular funding was unveiled, 10 of the twelve colleagues that participated in the study retracted their names from it. That same year The Lancet retracted the publication of said study, erasing it from their archives.

The General Medical Council, an organization dedicated to protect patients and improve UK medical education and practice by supporting students, doctors, educators and healthcare providers indicated, in 2004, that Andrew Wakefield showed cruel indifference towards children’s suffering, subjecting them to invasive procedures (colonoscopies and spinal taps) without the approval of an ethics committee. In 2010 the GMC took away his medical license, leaving him unable to practice medicine in the United Kingdom.

Besides all the damage caused by Mr. Wakefield´s fraud on vaccines and autism, one must also consider all the energy, money and human resources that have been used to demonstrate his study was false and that there is no correlation between vaccines and autism. All these resources could have been used to study the real causes of autism and to help children, adults and their families who live daily with this condition.



By Vaccinationist – PubChem, Public Domain,

Thimerosal is an organic compound containing mercury, known for it´s antiseptic and anti fungal properties. It was patented in 1927 and commercialized by Eli Lilly as Merthiolate a topical antiseptic which was also used as an ingredient in creams, gels, ointments, eye drops, nasal sprays and vaccines.

It has been shown that only inorganic mercury (the one you find in old fashioned thermometers) has a neurotoxic effect, but when mercury is in an organic environment, as it is in thimerosal, there is no incidence of neurologic harm.

In 1928 twelve children died after receiving a dose of the diphtheria vaccine which was contaminated with Staphylococcus. Given this incident, the use of preservatives in vaccines was considered. Unlike other preservatives, thiomersal does not affect the potency of vaccines, so manufacturers started using it in multidose vaccines, where one vial is used for several doses of the vaccine, because they are more susceptible to bacterial infection. Multidose vaccines are used because they are less expensive than single-dose. Antiseptics such as thimerosal are not needed in single-dose vaccines, the MMR, chicken pox, polio and Pneumococcus vaccines have never contained thimerosal.

There is scientific consensus about the lack of evidence that can back the allegations that relate the use of thimerosal in vaccines and autism. Furthermore, it has been reported that autism rates have gone even after thimerosal has been eliminated from vaccines; this is contrary to what would be expected if thimerosal use was linked to autism. The World Health Organization (WHO), FDA (Food and Drug Administration)and CDC (Center for Disease Control) reject any relation between the use of thimerosal and autism or other neurodevelopmental disorders.

Herd Immunity

When an important proportion of a community is immunized against a contagious disease, most of the members of that community are protected from that disease because there is little opportunity for a breakout. This is known as herd immunity.

After the introduction and generalized use of a vaccine, an important decrease in the incidence of the disease against which it protects and a decrease in the number of hospitalizations and deaths due to said disease. 

People who cannot be vaccinated depend on herd immunity to avoid contracting diseases. These include newborn babies, who have not received, or have only partially received immunization, people who are too sick to be immunized, immunodepressed or immunosuppressed patients and people who have known allergies to  components of one or more vaccines.

Recent outbreaks 

Recent outbreaks of vaccine preventable diseases in the US, Europe and other countries have taken physicians, public health personnel, the media and general public to pay more attention to the growing phenomenon of vaccine refusal.

In 2014 there were 23 measles outbreaks in the US, including the Disneyland episode in Anaheim, California, where there were 668 reported cases. Specifically in the Disneyland break there were 111 reported cases in 7 states, Canada and Mexico, where almost half of the congaed were people who had nos received their vaccines, even though they had no health issue that prevented them from being vaccinated.

In 2010 there was an outbreak of whooping cough in California with 9154 reported cases, and in 2014 there was a second break, also in California, with almost ten thousand cases.

Chile also had whooping cough outbreaks in 2012 and 2017.

Diseases that can be prevented by the use of vaccines

vacunas - sarampión vaccines

Measles: Measles is a highly contagious disease, the symptoms include high fever (40ºC or 104ºF), cough, nasal secretion and swelling of the eyes. tow or three days later white spots appear in the oral mucosa, then a flat red rash starts in the face and spreads through the whole body. Symptoms appear 10-12 days after virus exposure and last 7-10 days. 30% of the cases present other complications such as acute diarrhea, blindness, cerebral swelling and pneumonia, among others. There is no specific treatment of measles

Mumps: Highly contagious viral disease, early symptoms include fever, muscular pain, headache and fatigue. This is followed by the painful inflammation of one or both parotid glands. These symptoms appear roughly two weeks after exposure and remove after 7-10 days. Symptoms in adults are usually more severe than in children. Complications include meningitis, pancreatitis, permanent deafness and ovarian or testicular inflammation that can result in irreversible infertility.

Rubella: it starts with a rash that appears around two weeks after exposure and lasts for 3 days. It starts in the face and quickly spreads to the rest of the body. Lymph nodes usually become inflamed, which can last up to two weeks. Adults usually feel pain in their joints. Complications include hemorrhages, testicular inflammation and nerve inflammation. Infection during the first trimester of pregnancy can result in miscarriage or birth of a child with congenital rubella syndrome, which includes cataracts, deafness, heart (pulmonary artery stenosis), brain (microcephaly and intelectual disability) and liver problems (hepatomegalia).

Whooping cough: highly contagious bacterial infection whose symptoms are similar to the common cold, including mild cough, nasal secretion and fever. This is followed by weeks of severe coughing episodes where the patient con cough so hard as to vomit, fracture ribs or end up severely fatigued. Children under one year of age may not present cough but have apnea episodes that require hospitalization. Symptoms appear one week after exposure and can last up to 10 weeks (two and a half months). Treatment includes antibiotics, which have no effect on the cough, which presents for weeks anyway.

Diphteria: bacterial disease, its symptoms start 3-5 days after exposure. They appear gradually, starting with a sore throat, fever (38ºC or 100,5 ºF), followed by chills, fatigue, difficulty and pain when swallowing. Lymph nodes in the neck may become swollen. In 2-3 days diphtheria can destroy healthy tissue of the respiratory tract, dead tissue forms a thick gray layer inside the nose and throat, causing difficulty breathing and swallowing. Complications include myocarditis (inflammation of the heart muscle, resulting in irregular heartbeat), inflammation of the nerves (leading to paralysis), renal damage and coagulation disorders due to low platelet count.

vacunas - tétanos vaccines

Muscle spasms  in a person with tetanus. Painting by Sir Charles Bell, 1809.

Tetanus: bacterial non-transmissible disease, bacteria enter the body through a wound or cut in the skin produced by a contaminated object. Bacteria produce toxins that interfere with muscle contractions, producing muscular spasms. These start in the jaw and extend to the rest of the body. Sometimes the spasms can be so strong as to produce bone fractures. Other symptoms include fever, sweating, headaches, difficulty swallowing, hypertension and tachycardia. Symptoms present 3-12 days after exposure, can last several weeks and take months to achieve full recovery. 10% of infected patients die.

vacunas varicela vaccines

Chickenpox: highly contagious viral disease that develops a characteristic rash that forms small, itchy blisters that eventually scab over. It starts in the head and spreads to the whole body. Other symptoms include fever, fatigue and headaches. Symptoms present 10-21 days after exposure and last 5-7 days. Some complications include pneumonia, brain swelling and bacterial infections in the skin. The disease manifests more severely in adults.

Pneumococcus: produced by infection by Streptococcus pneumoniae bacteria and is responsible for 15-50% of pneumonia cases, 30-50% of middle ear infections and bacterial meningitis cases. WHO calculates that in 2005 pneumococcus infections killed 1.6 million people worldwide, 1 million of them being children under the age of 5. Most deaths occurred in developing countries.

As you see, none of these diseases is mild or lacking in complications, none of them has easy treatment. Many time they require hospitalization and rigorous control to prevent spreading to sensitive patients, like newborn babies, people with compromised immune systems, patients with cancer o people who have received organ transplants. There can also be severe consequences from the disease. This is why it seems so hard to understand that people would be willing to expose themselves or their children to contracting them, when they can be so easily prevented using vaccines. 

Given there is no scientific evidence to justify the fear of vaccines, I cannot understand why so many people would prefer that their children be at risk of contracting any of these horrible diseases rather than protect them with something as simple and safe as vaccines. 



2.- Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention, Institute of Medicine (2004). Immunization Safety Review: Vaccines and Autism. Washington, DC: The National Academies Press.

3.- Bigham M, Copes R (2005). «Thiomersal in vaccines: balancing the risk of adverse effects with the risk of vaccine-preventable disease». Drug Saf. 28 (2): 89–101.

4.- Gołoś, A; Lutyńska, A (2015). «Thiomersal-containing vaccines – a review of the current state of knowledge.». Przeglad epidemiologiczny. 69 (1): 59–64, 157–61.

5.- Offit PA. Thimerosal and vaccines a cautionary tale. N Engl J Med. 2007; 357:1278-9.




9.- The Editors Of The Lancet (February 2010). «Retraction – Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children». The Lancet. 375 (9713): 445.

10.- Rashid, H; Khandaker, G; Booy, R (2012). «Vaccination and herd immunity: What more do we know?». Current Opinion in Infectious Diseases. 25 (3): 243–9.

11.- Fine, P.; Eames, K.; Heymann, D. L. (1 April 2011). «»Herd immunity»: A rough guide». Clinical Infectious Diseases. 52 (7): 911–6.

12.- Halvorsen R (2007). The Truth about Vaccines. Gibson Square. 

13.- Phadke, Varun K.; Bednarczyk, Robert A.; Salmon, Daniel A.; Omer, Saad B. (15 March 2016). «Association Between Vaccine Refusal and Vaccine-Preventable Diseases in the United States». JAMA. 315 (11): 1149–58.




17.- Atkinson, William (2011). Epidemiology and Prevention of Vaccine-Preventable Diseases (12 ed.). Public Health Foundation. pp. 301–323.

18.- Lambert, N; Strebel, P; Orenstein, W; Icenogle, J; Poland, GA (7 January 2015). «Rubella.». Lancet. 385: 2297–307.

19.- Atkinson, William (May 2012). Diphtheria Epidemiology and Prevention of Vaccine-Preventable Diseases (12 ed.). Public Health Foundation. pp. 215–230.

20.- Atkinson, William (May 2012). Tetanus Epidemiology and Prevention of Vaccine-Preventable Diseases (12 ed.). Public Health Foundation. pp. 291–300. 



23.- Verma R, Khanna P (2012) Pneumococcal conjugate vaccine: A newer vaccine available in India. Hum Vaccin Immunother 8(9)