If you have been following the 2016 US presidential elections, you are, in all likelihood, aware of the controversy surrounding mandatory childhood vaccination.
The first time the body encounters a pathogen, it takes days to assemble enough antibodies to defeat the infection.
In that time, the pathogen has the opportunity to attack the body, causing us to experience symptoms of illness.
When a pathogen , such as harmful bacterium or virus, infects the body for the first time, the immune system  will quickly recognize it as an “invader” based on molecular features specific to the pathogen (known as antigens) (Figure 1A).
In response to these antigens, the body produces molecules called antibodies  that enable our immune system to track down and kill the pathogen.
Baker III Institute for Public Policy at Rice University, Houston, Texas, United States of America.
He is the author of Forgotten People, Forgotten Diseases (ASM Press), Second Edition. After this first encounters, the body will memorize what the antigens look like, so that if the same pathogen strikes again, we will be able to launch a stronger, faster defense against future invasions. Specifically, vaccines contain the same antigens as pathogens (Figure 1B), but in a weakened or dead form, so that the body can learn what the pathogen looks like and produce antibodies (Figure 1C) in a safe and comparatively controlled manner. Thus, when the body encounters the real pathogen, it is already trained and ready to eliminate the pathogen before it can do any damage (Figure 1D). According to the paper summary: “Here we gave nonhuman primate infants similar vaccines given to human infants to determine whether the animals exhibited behavioral and/or neuropathological changes characteristic of autism.No behavioral changes were observed in the vaccinated animals, nor were there neuropathological changes in the cerebellum, hippocampus, or amygdala.Herd immunity protects the entire population, even those who are not vaccinated are protected from disease. The percentage of the population that must be immunized to achieve herd immunity varies for individual diseases, with thresholds for common diseases ranging from 75-94% . Herd immunity is crucial to protecting those who are not eligible for vaccines, such as infants, pregnant women, and immunocompromised adults. ”Varicella vaccine effectiveness and duration of protection.” CDC. This means that while vaccines may seem like a personal choice, vaccination protects the entire population—and accordingly, failure to vaccinate could have negative population-level consequences. (A) Pathogens such as bacteria and viruses have molecular signatures called antigens (green triangles) that can be recognized by the body’s immune system. Today, anti-vaccinationists (sometimes known as “anti-vaxxers”), who include parents, politicians, religious leaders, and more, strongly oppose vaccination, particularly childhood vaccination. At its core, the anti-vaccination movement argues that vaccines are unnecessary, ineffective, or dangerous. A closer look at the evidence surrounding vaccinationists suggests that while the anti-vaccinationist ideals are compelling, a more accurate picture of vaccination may be found elsewhere.