The denial of science

Do you believe in science? When you have people who do not know much about science and stand in denial that is a recipe for the dismantling of an informed society.

Neil de Grasse Tyson, an American astrophysicist, author and science communicator, said that when he grew up, people relied on science to drive innovation. But no longer. “People have lost the ability to judge what is true and what is not, what is reliable, what is not reliable. I don’t remember any other time where people were standing in denial of what science is.”

The good thing about science is that it’s true whether or not you believe in it.

Science is basically an inoculation, a vaccine, against charlatans and throughout human history never was ignorance better than knowledge.

The development of science has made available for humanity many extraordinary “health tools”, that extend life in a healthier way. No other health tool has been as cost-effective and successful at saving lives as vaccines, particularly among children.

Safety and performance are two of the most important factors in the development of a vaccine, and both are priorities of the clinical development process.

Even after a vaccine has been licensed and is in use, monitoring continues in order to ensure that any new information gathered after the product has been licensed is evaluated by experts and shared with the public.

Standard immunisation currently averts an estimated two to three million deaths every year in all age groups. Without vaccines and effective vaccine distribution and delivery practices, disease would become more rampant, public health systems would be overburdened with treatment costs and deaths (particularly in children) would increase dramatically.

Immunisation is beyond doubt a valuable tool for protecting health, enhancing economic security and political stability, and saving lives.

Herd immunity

The direct effects of vaccination generally refer to the protection of the vaccinated individual, resulting in a reduced chance of infection and possible complications.

In contrast, the indirect benefits of vaccination refer to protective effects observed in unvaccinated populations. It is this indirect effect of vaccination that is known as the herd effect or ‘herd immunity’.

A high uptake of vaccines is generally needed for success. As an example, measles is a highly transmissible disease requiring that 90-95% of people must be vaccinated in order to protect the entire population, or achieve what is called herd immunity.

Herd immunity arises when a high percentage of the population is protected through vaccination against a virus or bacteria, making it difficult for a disease to spread because there are so few susceptible people left to infect. It is particularly crucial for protecting people who cannot be vaccinated. These include children who are too young to be vaccinated, people with immune system problems and those who are too ill to receive vaccines (such as some cancer patients).

The proportion of the population which must be immunised in order to achieve herd immunity varies for each disease but the underlying idea is simple: once enough people are protected, they will help to protect vulnerable members of their communities by reducing the spread of the disease.

Some can ask: If not everyone needs to get vaccinated in order to attain herd immunity, can it really be so bad if I opt out of it?

Herd immunity should not be used by people as a seemingly scientific justification for not getting vaccinated.

The sad truth is this: as long as there are communities that harbor strong negative views about vaccination, there will be outbreaks of vaccine-preventable diseases.

When immunisation rates fall, herd immunity can break down leading to an increase in the number of new cases.

The principle of community/herd immunity applies to control a variety of contagious diseases, including influenza, measles, mumps, rotavirus, and pneumococcal disease.


Vaccines are the best defence we have against serious, preventable and sometimes deadly contagious diseases. Vaccines are some of the safest medical products available, but like any other medical product, there may be risks. As anything in life, just being alive has many risks, but it is better to run some controlled risks to enjoy life at its best and avoid worse things happening.

If negative vaccination sentiments become more popular, we may start to see more sustained transmission chains and may again be in a situation of endemic outbreaks of infectious diseases, like measles.

There is an ethical argument to be made for the goal of 100% vaccination coverage. Everyone who can get vaccinated should get vaccinated, not only to protect themselves, but also to protect those who cannot, through herd immunity.
Vaccines can prevent outbreaks of disease and save lives.

When I hear people saying they have decided not to vaccinate their children, I recall having read somewhere, sometime ago, that we were never visited by aliens because they could not find on Earth any sign of intelligent life…

Why should we deny science? Science is a complex exercise in finding the truth; it is not something you can choose not to believe.

When there is a scientifically established truth, it is true, whether or not you believe it.

There are truths that are true, if you believe them or not.

Opinions and decisions require knowledge and should always be based on certified knowledge.

The “freedom” not to vaccinate children or adults has severe negative implications on community health.

Liberty has limits drawn around us by the liberty and rights of others. We are not alone!

Best health wishes,
Dr. Maria Alice

By Dr Maria Alice
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Dr Maria Alice is a consultant in General and Family Medicine. General Manager/Medical Director – Luzdoc International Medical Service / Medilagos. Medical Director – Grupo Hospital Particular do Algarve