For vaccine opponents, a 0.000001 percent chance of severe reactions is too high to justify vaccinations, while a 0.0002 percent chance of death is too low to justify vaccinations.

People who reject vaccinations for preventable, deadly diseases are driving a new and dangerous wave of misinformation. This is causing a reduction in vaccination rates, leading to outbreaks of diseases such as measles across the country. We must combat this small but incredibly vocal minority, and use scientific objectivity to prevent them from driving vaccination rates further downwards.

Here are some of the most common arguments against vaccines, and a brief discussion of each, citing scientific studies for backup.

1. Vaccines Cause Autism

This is perhaps the strongest anti-vaccine rhetorical weapon, despite the fact that the 1998 study that claimed to show an association between the measles-mumps-rubella vaccine and autism was retracted, debunked, and shown to be fraudulent. As a result of his professional misconduct, Andrew Wakefield, the British doctor who produced the study, was banned from practicing medicine in the United Kingdom.

Multiple studies performed across the world have shown that there is no causal link between vaccines and autism, but the emotion and fear surrounding autism allows the anti-vaccine community to keep this myth alive.

TL;DR: There is no evidence to suggest that vaccines cause autism.

2. Do Your Research

Many vaccine critics base their views on “research” they have performed. The problem here is that the research may be performed with limited scientific understanding, lack of objective or critical thinking, using weak or false sources, and with the goal of justifying a preemptive conclusion.

The internet is full of convincing, pseudo-scientific information, with broad degrees of accuracy or inaccuracy on every topic you can imagine. When the vast majority of the worldwide medical community reaches the conclusion that vaccines are both safe and effective, any “research” that questions this conclusion must provide a large amount of relevant and objective scientific evidence.

TL;DR: Anyone can make a website. Relevant knowledge and experience matters. Demand objective evidence.

3. Vaccines Contain Mercury, Aluminum, and Antifreeze

Vaccine opponents continuously avoid scientific specificity regarding the details of vaccine ingredients such as demonstrated safety or dosage size, to terrify parents with vague references to scary-sounding ingredients such as mercury, aluminum, and antifreeze. Some influenza vaccines contain ethylmercury, known as Thimerosal, which acts as a preservative, and is different from the methylmercury found in fish.

A negligible amount of aluminum is sometimes used to strengthen the effectiveness of the immune system response, and the quantity of aluminum in vaccines doesn’t even cause any noticeable raise in the base amount of aluminum found in the infant’s blood, even if measured immediately after the vaccine is administered. Finally, to the claim that vaccines contain antifreeze: antifreeze is ethylene glycol, and vaccines contain polyethylene glycol.

TL;DR: The specific ingredient and dosage is crucially important. We can drink ethanol, but methanol is toxic. One ounce of ethanol is safe to drink, but a gallon will kill you. The presence of a specific substance is far less important than the context of its use.

4. You Decide For Your Kids, and I’ll Decide for Mine

This attitude highlights an ignorant attitude towards the science of vaccination. Firstly, vaccines are not 100 percent effective. Since vaccines use weakened or killed versions of the bacteria or virus, some individuals fail to develop full immunity. This means being vaccinated does not guarantee protection.

Secondly, not all people can be vaccinated for medical reasons, such as pregnancy, age, or compromised immune systems. This means that, despite some vaccination coverage, both the vaccinated and unvaccinated may be at risk. This is why the concept of herd immunity is so important, as a sufficiently vaccinated population provides protection for those who cannot be vaccinated for a valid, medical reason.

TL;DR: Being vaccinated as an individual is not enough, and the decision not to vaccinate affects others.

5. They Haven’t Researched Vaccines Enough, Or Combined Vaccines

Despite the clear hypocrisy that vaccine opponents consider their own non-scientific research valid while judging scientifically supported research invalid, many claim that not enough research has been done to prove that vaccines are safe. However, the reality is that vaccines are one of the most widely researched medical inventions in human history. Not only have millions of children across the world shown the safety and effectiveness of vaccines, vaccines are heavily investigated and tested, with study after study investigating their efficacy and safety.

TL;DR: Vaccines and combined vaccines have been thoroughly researched, and found overwhelmingly safe.

6. Vaccine Makers Admit to Risks of Side Effects

Every medication has possible side-effects, as well as the risk that it may trigger an allergic reaction. Statistically, serious side-effects of vaccines are extraordinarily rare, with an estimated 0.000001 percent of people experiencing severe reactions.

With millions of children vaccinated in the United States, and billions worldwide, viewing these cherry-picked and statistically rare cases through the lens of the internet and social media provides the implication that so-called “vaccine injuries” are common. While it is undeniably awful for those who do experience severe reactions, and undoubtedly traumatic for their parents and families, basing the rejection of vaccines on 0.000001 percent of cases is purely unscientific.

Diseases like measles and polio do 100 percent of the time threaten a person’s health and even life. The same is not anywhere close to true of vaccines to prevent these diseases. If you’re doing a risk calculus, it is obviously on the side of vaccines rather than taking your chances getting the diseases they could prevent.

TL;DR: The real risk posed by vaccine-preventable diseases by far outweighs the risks posed by the vaccines themselves.

7. The CDC and Big Pharma Are Lying to You For Money

The views held by the U.S. Centers for Disease Control are largely consistent with those of medical institutions across the world, meaning that a global conspiracy that bridges even the largest political divides must exist for skepticism of CDC’s vaccine recommendations to be warranted. Vaccines are also far cheaper and mean far less suffering than treating the diseases they protect against.

History is full of revolutionary products that have both improved our quality of life and made their inventors wealthy. Why are profitability and efficacy mutually exclusive? Ironically, those who distrust Big Pharma for making money on vaccines don’t have the same disdain for those who profit on the distrust of the medical industry or the fear of vaccines.

TL;DR: The CDC shares its major opinions with the rest of the world’s medical community, and making a profit doesn’t imply that the product or service is corrupt or fraudulent.

8. Do You Have Children? Is Your Child Vaccine-Injured? I Love My Children, and I Chose What Was Best for Them

This is an example of emotional manipulation, appealing to basic human psychology. When discussing a topic based on scientific facts, parental status is irrelevant. Can men have opinions about the science of ovarian cancer? Can women have opinions about the science of testicular cancer? The claim that one’s opinion regarding vaccines only has any validity if you are a parent is absurd.

Secondly, by stating that they, after careful research, made these choices due to their love for their child, people who make this argument subtly imply that those who do not come to the same conclusion do not hold the same love for their children. This is clearly illogical, but is an attempt to steer the debate away from fact-based objectivity into emotional subjectivity, where two ideologies are in competition to be the “most loving.”

TL;DR: If I did have children, would that change your mind? Don’t use your love for your children, or whether I have children, to deflect fair criticism.

9. Why Do We Even Need Vaccines?

Measles alone killed 2.6 million people worldwide in 1980, a number reduced to 73,000 in 2014 due to global vaccination programs. Before the measles vaccine was introduced, almost every child in the United States caught the measles, with an estimated 3 to 4 million infections each year. With an annual rate of 400 to 500 deaths, 48,000 hospitalizations, and 1,000 cases of encephalitis before vaccination in the U.S, approximately 0.0002 percent of those who caught the measles died.

People were 167 times more likely to die from measles before the vaccine existed than to suffer severe reactions to the vaccine today. However, for vaccine opponents, a 0.000001 percent chance of severe reactions is too high to justify vaccinations, while a 0.0002 percent chance of death is too low to justify vaccinations. This clearly makes no mathematical sense.

TL;DR: Vaccines save millions of lives.

10. The United States Recommends More Vaccines Than Other Countries Do

This is demonstrably untrue. The World Health Organization has shown that many countries have an almost-identical vaccine schedule to the United States.

TL;DR: No they don’t.

Yes, parents should question the science about vaccines in order to make the right decision for their children. However, it is important that these decisions are made objectively, valid research is respected, and in a debate free from misinformation, emotional manipulation, and lies.

Debating with a vaccine critic may feel like a game of logical whack-a-mole—when one line of reasoning is debunked, another one appears. However, it is a game that we must keep playing. Otherwise, we are in danger of sleep-walking away from the life-saving medical advances previous generations have made, and returning to a time where preventable deadly diseases are a more frequent reality, instead of a medical horror resigned to the pages of history.