The truth about vaccines

Note: This blog was originally written for Know Science and is mirrored here.

I believe that knowledge of science can empower people to make better decisions for their health and lives. When it comes to vaccine, that decision could be a life or death one.

When I heard about the breaking news today, reporting that a six-year-old Spanish boy who had become infected with Corynebactuerium diphtheria earlier this last month, died of diphtheria[0], I could not believe this would happen in 2015. This is the first case of diphtheria in Spain in 29 years since widespread vaccinations have allowed successful eradication of the disease worldwide. The boy, however, was not vaccinated against diphtheria because his parents were against him getting inoculated amidst controversies over the shot’s potential side effects. In the small Spanish town of Olot 10 more people, of which 9 children, were exposed to the bacterium but did not develop the disease as they were all vaccinated.

FROZEN_CELLS_SG_2In the last 10 years, the world has seen parents all over the world rejecting vaccination. Parents have attempted to find answers to aid their decision but getting information on vaccines from the internet can be a scary and confusing experience.  I’d like to provide some answers to the more recurrent concerns the public faces when thinking about vaccines based on rigorously tested scientific and epidemiological evidence.

I hope this information can be useful to you and can help avoiding the re-occurrence of preventable diseases.

In the last five years, there has been a decrease in the number of parents vaccinating their children[1].  So what?

About 800 people die a year as a result of parents not vaccinating their children. Basically, two people every day in the United States alone die of causes that could have been prevented by vaccinations[2] [3]

What about the potential risk of deaths from vaccination?

Severe and extreme reactions to vaccination are extremely rare. As with any drug or medicine, there is a small chance that vaccines may cause an adverse reaction. Every year in the United States, millions of people are vaccinated for a wide range of diseases and fewer than 1% have non-life threatening allergic reactions to the vaccine. The rate of death or severe reactions to vaccines, for instance the MMR shot, is less than one in a million vaccinations4. The rate is so low, it is actually difficult to be certain the adverse reaction was directly linked to the vaccine[4]. To put that in perspective, Tylenol poisoning[5] kills more than 100 people every year.

What about the lives that vaccines save?

Vaccines save millions of lives worldwide every year. Perhaps the most impressive result of a vaccination can be seen with the smallpox vaccine.  In the past, about 80% of children and half of the adults infected with the smallpox virus died of this devastating disease.  Two million people died every year during the 1960s from smallpox. Aggressive vaccination campaigns led to the complete eradication of the disease – that’s right, nobody in the world is infected with smallpox these days! The last smallpox case was diagnosed in 1977[6]. Thanks to this vaccination, the world went from 2 million deaths to zero in less than 10 years.

What about mercury, and other potentially toxic substances contained in vaccines?

Mercury hasn’t been used in vaccines since 2001. All routinely recommended childhood and adult vaccinations, and most influenza vaccines to date, do not contain mercury. While there may be other ingredients in vaccines, such as preservatives, stabilizers and enhancers, they are all FDA-approved7.

Vaccines can contain small amounts of formaldehyde and aluminium but the amount of these substances in vaccines is several hundred times lower than what we are routinely exposed to in our diet. This is the same for traces of mercury in some flu vaccines[7].

Mercury hasn’t been used in vaccines since 2001.

Do vaccines cause autism, ADHD, and other non-lethal disorders?

No link has been proven between autism and vaccines. Since the 1950s, mass vaccination of millions of infants and adults has been occurring, preventing thousands of deaths[8].  The fraction of children affected by autism is currently 1 in 68 which means that just 1.7% of children suffer from autism. Right now, about 90% of children receive vaccinations. Just looking at the numbers, vaccines are unlikely to be the distinguishing factor that confers susceptibility to autism.

Why do people say there is a link between vaccines and autism?

The unfounded link emerged from a fraudulent scientific study[9] that kick-started much of the largely unfounded mass hysteria about vaccines that we witness today.  The study was retracted10 and the doctor responsible for the fraud was banned from any future research. By then, however, the damage had been done. After the fabricated study was reported, many labs attempted to find evidence for a link between vaccines and autism without success, which further discredits the original “research”[10]. There have been hundreds of studies disproving the link, showing with great statistical significance and confidence, that there is no link between vaccines and autism.

I don’t like the fact that my newborn child has to get multiple vaccination shots. Is it harmful for the baby?

Newborns are tougher than you think! The amount of immune challenges young children fight daily is a thousand times greater than all life-time vaccination doses combined. Already at birth, the passage from the secure environment of the womb through the bacteria-filled vaginal canal is a shock to the baby’s immune system – a good shock! Caesarean birth has been associated with higher risk of allergies, asthma and inflammation[11] later in life because the baby is not exposed to those immunity-inducing bacteria. Vaccines have a similar effect. Challenging the infant immune system with vaccines is a safe way[12] to get it to work against preventable diseases. While we live in an environment that offers fewer challenges to the immune system (where we over-sterilize and don’t “let the babies play in mud anymore”), vaccinations are actually a great way to exercise the immune system and keep all its parts functioning properly.

Are vaccines makers just making money from vaccinations that are not actually for our own good?

Most vaccines are cheap for patients. The evidence for the benefit of vaccines is so overwhelming[13] and the consequences of not vaccinating so catastrophic, that vaccines are made by many pharmaceutical companies and the process is cheap. [14]

You are saying, basically, that I should vaccinate my children. Yes?

Yes! Decades of scientific and medical research have made it possible for us to virtually eradicate diseases preventable by vaccinations. In the last century, childhood mortality in developed countries has decreased 99%[15], largely due to vaccines and antibiotics. Many charities, foundations and organizations promote important immunization campaigns for preventable diseases in developing countries. Why would the leading nations that have worked to advance science and human health through vaccine discovery want to stop taking advantage of that?

Shouldn’t we let parents be free to make their own choice about vaccination?

Disease protection derived from vaccines doesn’t work on individual choices, it must be a collective effort involving all the members of a society (especially, in the globalized world of today). Vaccination rates must stay high to keep a whole community protected from a certain disease, a concept called ‘herd immunity’[16]. The rates required to continue preventing outbreaks and epidemics of certain diseases are variable, with 85% immunization rate needed to protect us from polio and 95% required to eradicate the highly contagious and deadly measles. The people with the highest risk from these diseases are young children, immune-compromised individuals – such as cancer patients – and the elderly. Our need for each individual to vaccinate is even greater to ensure that the whole community, even those with the highest risk, remains healthy. Vaccinations are not about individual choices, but about social responsibility and safety.

Fine, I see the benefits of vaccines but are all vaccines equally necessary? For instance, against seasonal flu?

Annual leading causes of death in USA.

Influenza is the 7th most deadly disease in the United States, right behind diabetes.  Every year, 55,000 adults and children die from the flu and pulmonary complications derived by the flu, while severe adverse reactions to the flu shot are 0.00000001%, so why not vaccinate? Also, remember the concept of herd immunity discussed above. Not vaccinating against the flu means exposing more people to the virus for a prolonged period of time, including immune compromised individuals. An immunized person that comes in contact with the influenza virus clears the infection in 24 hours. A non-vaccinated person is infected and contagious for almost a week, often asymptomatically at first, which dramatically increases spreading of the disease. It is also important that the flu vaccine is taken yearly.

Asking questions about vaccines is expected, just like any other medication. However, be sure to take immunization advice from your doctor, immunologist, or a medical expert on vaccinations. Refrain from drawing conclusions based on assumptions, personal beliefs, or information from unreliable sources. After all, it’s a choice about life: yours, your kids and everyone that comes in contact with you in your lifetime. Make that be the right choice.

Thanks for reading,

Dr. Simona Giunta, Ph.D.

President of Know Science

This blog was made possible by sharing the knowledge and information collected from several scientists and immunologists, and is based on real questions submitted by the Know Science audience. Special thanks to Professor Juan Lafaille, Kate Bredbenner, Danielle Sonnenberg and Alistair Field for critical reading and expert advice. We welcome any additional questions you may have via our Ask The Expert form and we encourage your comments below.




[2] Further reading on the Centre for Disease Control and Prevention website. What would happen if we stopped vaccinations?


[4] American Association of Poison Control Centers. Practice Guideline: Acetaminophen Poisoning: an Evidence-Based Consensus Guideline for Out-of-Hospital Management. Clinical Toxicology, 2006: Vol. 44; pp. 1–18.

Wolf SJ, Heard K, Sloan EP, Jagoda AS; American College of Emergency Physicians. Clinical policy: critical issues in the management of patients presenting to the emergency department with acetaminophen overdose. Ann Emerg Med. September 2007: Vol. 50; pp 292-313.







[12] Updated aluminum pharmacokinetics following infant exposures through diet and vaccination. Vaccine 29 (2011) 9538-9543





Life of a Cancer Cell

Cancer, a word that has more than 700 million hits on Google, that features in 100 million news articles and affects, directly or indirectly, the majority of the world population, still remains a mystery to us.

So, what is cancer and where does it come from?

We have trillions of cells in our body and cancer comes from a single one of those cells. Every day, each cell in our body is exposed to agents that cause damage to the DNA. These agents can be external, such as UV light while sitting in the sun, radiations from an x-ray scan, alcohol consumption (1) [1], smoking (2), pollutants (3) [2], burnt food [3], food chemicals (4) [4] and many more, all acting as attackers to the DNA; on top of these, internal agents, like oxygen free radicals, are also damaging to the DNA. The truth is that, if we sat in a dark room, drinking nothing but water, and breathing only clean air, our cells living their daily life (and carrying out essential cellular processes) still get damaged in their DNA. Indeed, every day, each individual cell suffers up to a million lesions to the DNA. Multiplied by every cell in our body, that’s a huge amount of damage to be repaired!


A flower of cells

Confocal microscopy image of human osteosarcoma cancer cells that show damage to their DNA (green and red dots). DNA stained in Blue.
Image by Simona Giunta

However, fear not, our body is perfectly equipped to handle it! We’re able to repair the damaged DNA and have proteins in our cells designed to efficiently detect and identify basically every type of DNA damage within seconds from their occurrence; these proteins work hard 24/7 to repair the damaged DNA and maintain the cell open and operative for its usual cellular business!

You can imagine, though, that there might be times when the damage covers a very large area of DNA and it’s too extensive to be repaired. Even in this situation, the cell is smart and is able to assess when it’s too badly affected and knows when it would be impossible to repair such large damage. In this case, the cell makes the executive decision to commit suicide. Cells in the body work as an altruistic society, where all aim to contribute to the greater good of the body in a selfless way. The health of the whole body is more important than the life of an individual cell, especially if damaged. Thus, the cell that is too badly damaged and basically unable to function, or to function properly, will activate a ‘programmed cell death’ process, called apoptosis.

‘Apoptosis’ is a word that derives from Greek, meaning ‘falling away’. Like leaves from the tree, apoptotic cells ‘fall away’ from our body. A good example of apoptosis due to DNA damage is our skin peeling after sun burnt, representing thousands of cells literally falling off our body.

The destiny of a damaged cell that can no longer act in a positive manner toward the health of the whole organism is cell death, removing itself to avoid being potentially deleterious to the entire system.

The cancer cell, on the other hand, is a selfish cell that doesn’t want to die! It’s a badly damaged cell that, childishly, throws a tantrum, moaning “I don’t want to die! I don’t care I am damaged, I am staying put, I’m not going anywhere!”. The cancer cell is individualistic and does not face up to the reality of its situation of being too damaged to function. In fact, the cancer cell doesn’t care it can no longer contribute to the good of the body, it merely thinks of itself and its own survival. Obviously, that is a short-sighted view on the cancer cell side, as the survival of a single – badly damaged – cell can become dangerous and possibly lead to the death of the body! Our body, though, is also equipped to act against these ‘selfish’ cells that do not die, mounting an immune response against them and getting rid of them.

Although the anthropomorphization of the cancer cell as a selfish cell is suited, even from a biological stand point, the scientific truth behind the cancer cell is that the cell knows it should die, would actually like to die, but the cancer cell cannot die! What happens is that this cell is damaged right in the point of the DNA that it needs to read to be able to know how to die and activate the cell death pathway! It would like to die, but doesn’t know how to! This is, somewhat, a rare event as we have 6 billion pieces of code in our DNA, the so-called DNA letters (A T C G, respectively: adenine, thymine, cytosine and guanine) and the fact that an unrepairable damage falls right in the point that the cell needs to access to know how to die it’s extremely unlucky! Of course, as we live longer lives, perhaps beyond our own evolutionary age, in this increasingly polluted Earth, drinking alcohol, smoking and eating processed, semi-synthetic, chemicals filled food, exposed to dangerous toxins, you can see how, day after day, cells get increasingly damaged. Been damaged over and over, the probability that a cell in the body loses control over it’s own ability to die, to divide, to live life in a calm, paced manner and instead starts speeding through life – as some of us also do – is not so unlikely after all!

And this could be the reason why cancer incidence increases hugely with age and the way we live also has a clear role in this. Several scientific evidence show that about 60% of cancers are what scientists call ‘sporadic’ cancers [5], which have not been found to be directly influenced by our genes and genetic make-up, but can be considered life-style induced. The remaining ~ 40% are the ‘hereditary’, ‘familiar’ and genetic cancers, often childhood cancers belong to this category, where the body has inherited a mutation from the parents that does not allow cells to function properly or that makes them defective in repairing DNA damage correctly – as for Angelina Jolie with an inherited BRCA1 mutation [10], hence, making the person more susceptible to cancer and at risk of developing cancer at a much earlier age.

As a cancer researcher, I get asked almost on a daily basis this question: do we have a cure for cancer yet?

And, inherited cancers aside, the best cure for cancer, honestly, is prevention!

If you think that lung cancer is the most common cause of cancer-related death worldwide [6] and that 4 in 5 lung cancer are caused by smoking [7], just by stopping smoking, we could reduce those 4/5 of lung cancers, 1 million death each year, and almost one fourth of all cancer death across the globe! [8]

Because cancer is not just one but hundreds of heterogeneous diseases, where each needs it’s own medical treatment and management, prevention is extremely important, across the spectrum of all cancers, more than any cure from any Nobel Prize winner biologist (although those cures become essential once cancer is already present)! Because the very first steps in a cancer cell’s life is the DNA damage leading to a mutation, and this very first event in carcinogenesis is common in all types of cancers, minimizing DNA damage through prevention is the best action in fighting cancer.

Minimizing damage to our DNA is the best thing we can do to fight cancer

Sure, changing our lives, living better, eating better (for starter, at least 400 gr of fresh vegetables and fruit a day, as from WHO recommended guidelines [9]), avoiding harmful chemicals, quitting smoking, demanding clean air and water, exercising, all of these activities combined are by no means a guarantee of a cancer-free life. During our long lives, it might still happen. However, I like to put it down to the ‘crossing the road’ theory of probability:

When you are crossing a road, it is highly recommended that you look before crossing. Nonetheless, it is not actually 100% guaranteed that looking will save your life. You might look carefully before crossing, then, in a moment of bad luck, a car comes from around the corner at fast speed and hits you! On the other hand, you could decide to cross the road without watching and you could be lucky to do it when no one is coming and never get hit (unlikely in New York and any other city in the world, so don’t do it!). Sure, it’s unluckily and that’s the same for cancer. If you live carelessly, you might always be lucky and never get hit. Vice versa, you could lead a healthy life, yet still get cancer. But as a general rule, if you live well, you decrease your chances to have cancer (and many other diseases!) enormously and if you live badly, well… who would be so crazy to cross a road without looking anyway!!!

The Beatles crossing Abbey road without looking!

The Beatles were not looking for incoming traffic and were lucky not being hit crossing Abbey Road! Similarly, millions of people in the world live “without looking”, posing themselves at an increased cancer risk. Don’t be reckless, no crossing/living without looking!

The secret is right in our hands. We could be lazy about it, maintaining the status quo and just waiting in the hope that scientists come up with a magic pill after years of of lab work and more years for clinical trials, drug approval and commercialization, and then pay thousands of dollars for the entire treatment or… we could act now to change not only our life, but also our planet for the better, for good!

On this note, I urge every single soul on this planet to look before crossing the road, to wake up tomorrow and take ownership of their lives and their world, and to make a change for the better, for the greater good of this amazing thing we live in – our body!


Dr. Simona Giunta, Ph.D. and Cancer Researcher.


1.         N. Kotova et al., Carcinogenesis 34, 325 (Feb, 2013).

2.         C. S. Kao-Shan et al., Cancer Res 47, 6278 (Dec 1, 1987).

3.         R. Andreoli et al., Med Lav 103, 324 (Sep-Oct, 2013).

4.         Y. F. Sasaki et al., Mutat Res 519, 103 (Aug 26, 2002).



[1] ” […] we demonstrate that an intake of 10% alcohol for 4 weeks in rats is genotoxic due to induction of micronuclei. Acetaldehyde (AA), the first product of ethanol metabolism, is believed to be responsible for DNA damage induced by alcohol.”

[2] Biomarkers of exposure to benzene increased as a function of environmental air pollution and urbanization level; (ii) U-Benz clearly distinguished both exposure to ETS and areas of residence, whereas benzene metabolites were associated only with the latter; (iii) the variance of 8-oxodGuo and 8-oxoGuo was accounted for by environmental benzene exposure, thus suggesting that benzene is a good tracer of other components of complex mixtures of pollutants causing oxidative damage to nucleic acids.

[3] One solid reason to not eat burnt food is that it contains polycyclic aromatic hydrocarbons (PAHs), which are a class of air pollutants. Some of these chemicals have been proven to be carcinogenic, and some are even found in coal tar and cigarette smoke. The toxicity of PAHs depends heavily on its structure; while many PAHs may have the same chemical formula and same number of rings, different isomers can vary from being nontoxic to being extremely toxic.

The most well-known of PAHs is benzo(a)pyrene, which damages DNA, which in turn can possibly cause cancer. Cooked meat products contain up to 4 ng/g of benzo(a)pyrenes and up to 5.5 ng/g in fried chicken. However, in overcooked beef, the amount of benzo(a)pyrene can reach over 60 ng/g.

[4] ” We determined the genotoxicity of 39 chemicals currently in use as food additives. They fell into six categories-dyes, color fixatives andpreservatives, preservatives, antioxidants, fungicides, and sweeteners. We tested groups of four male ddY mice once orally with each additive at up to 0.5xLD(50) or the limit dose (2000mg/kg) and performed the comet assay on the glandular stomach, colon, liver, kidney, urinary bladder, lung, brain, and bone marrow 3 and 24h after treatment. Of all the additives, dyes were the most genotoxic. Amaranth, Allura Red, New Coccine, Tartrazine, Erythrosine, Phloxine, and Rose Bengal induced dose-related DNA damage in the glandular stomach, colon, and/or urinary bladder. All seven dyes induced DNA damage in the gastrointestinal organs at a low dose (10 or 100mg/kg). Among them, Amaranth, Allura Red, New Coccine, and Tartrazine induced DNA damage in the colon at close to the acceptable daily intakes (ADIs). Two antioxidants (butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT)), three fungicides (biphenyl, sodium o-phenylphenol, and thiabendazole), and four sweeteners (sodium cyclamate, saccharin, sodium saccharin, and sucralose) also induced DNA damage in gastrointestinal organs. Based on these results, we believe that more extensive assessment of food additives in current use is warranted.”

[5] Sporadic cancers – these are cancers that occur by chance in individuals who have no known genetic risk factors and no significant family history. Approximately 60% of cancers are sporadic.

[6] Wiki: Worldwide, lung cancer is the most common cause of cancer-related death in men and women, and is responsible for 1.38 million deaths annually, as of 2008.[11]

[7] SMOKING IS THE SINGLE BIGGEST CAUSE OF CANCER IN THE WORLD. ” Experts agree that smoking is the single biggest cause of cancer in the world. Smoking causes over a quarter of cancer deaths in developed countries and nearly one in five cancer cases. Around half of current smokers will be killed by their habit if they continue to smoke. And 25-40% of smokers will die in middle age. Smoking causes even more deaths from other respiratory diseases and heart conditions than from cancer. If current trends continue, scientists estimate that tobacco will kill about one billion people in the twenty-first century. Smoking greatly increases the risk of lung cancer. A 2011 study found that more than four in five lung cancers are caused by smoking. In 2002, lung cancer killed around 33,600 people – about one person every 15 minutes. Tobacco smoke was first shown to cause lung cancer in 1950. This study found that people who smoked 15-24 cigarettes a day had 26 times the lung cancer risk of non-smokers. And people who smoked less than 15 cigarettes a day still had 8 times the lung cancer risk of non-smokers.”