When it comes to vaccinations, the general public is still exposed to strong supporters of conspiracy theories, misunderstandings, and general bunk concerning the practice. I'd like this thread to be open to discussion involving anything about vaccines. I'm not covering the autism idea in this post because it has been brought up in other threads and thoroughly debunked, but if you have any questions feel free to ask. Instead I'm going to focus on ideas suggested in the following documentary that claims vaccinations do not help and, instead, harm people who receive them. I will not cover every claim and I will discuss some things not in the film in order to make this post as comprehensive as possible. Claim: One of the first claims brought up and is then talked about through the whole video is that the diseases vaccines were made to prevent were already declining before the vaccine was introduced. They suggest that this means the vaccines were not actually the cause for the decline in disease. Fact: Let's take the first one they talk about, the whooping cough (pertussis) vaccine as an example. Dr. Isaac Golden presents us with a graph that shows a declining incidence rate of pertussis and an arrow to represent the introduction of the vaccine in 1948, which by this time in the graph the incidence rate is relatively low. There are a number of problems with this. Most importantly, the arrow is pointing to the wrong time of pertussis vaccine use. When vaccines became successful and widespread, many different vaccines were mixed together into a single shot for efficiency's sake. For example, the Measles, Mumps, and Rubella (MMR) vaccine. The 1948 mark points to the introduction of the Diphtheria, Tetanus, and Pertussis (DTaP or DTP) vaccine. Regular pertussis vaccines, however, have been around since the 1920's when Louis W. Sauer^ created a successful vaccine. Others were successful and used the vaccines to help control outbreaks. http://www.nature.com/pr/journal/v55/n2/full/pr200452a.html (http://archive.is/HfWmf) Dr. Viera Scheibner then presents another graph to claim the same thing about diphtheria. In this case, and many like it, the graph is deceptive in the fact that it shows a limited time span and, most importantly, is measuring the deaths attributed to that disease. This hides the true success of vaccines, as decreases in incidence rates are much more telling. To illustrate that with the examples I've listed, here are the data for pertussis and diphtheria incidence rates. http://www.cdc.gov/pertussis/surv-reporting.html (http://archive.is/iFgXA) http://www.phac-aspc.gc.ca/im/vpd-mev/diphtheria-eng.php (http://archive.is/T4ByV) Another deceptive graph is the one presented about measles. Here are the real data. http://en.wikipedia.org/wiki/File:Measles_US_1944-2007_inset.png So the claim against vaccine effectiveness using these graphs turns out to be absolute bunk. Vaccines have been demonstrated to be hugely successful in reducing incidence of disease and even eradicating some nasty ones. Claim: Bronwyn Hancock, the narrator of the film, claims that immunized populations fare no better than non-immunized populations. Fact: Over the past few decades, especially with the emergence of anti-vaccination groups, there have been large groups of people who refuse to receive immunization. This unfortunate reality gives us the opportunity to address such a claim directly. In every case, immunized populations do, in fact, have lower incidence rates than non-immunized populations. One of the best examples I can think of is that of polio. Polio is close to eradication, but some countries still report relatively high incidence rates. These include countries in Africa, the Middle East, and Southeast Asia. Radical groups have claimed that polio vaccines are a conspiracy to infect Africans with HIV and this has caused many to forego vaccination. These theories have no basis and every batch of polio vaccine is tested for contamination. As a result, polio has spread among non-vaccinated populations. http://www.sciencemag.org/content/342/6154/28.full (http://archive.is/vtWag) Similar stories can be found in the United States. http://www.popsci.com/science/artic...ak-centered-around-vaccine-skeptic-megachurch (http://archive.is/6TgLB) Claim: Dr. Robyn Crosford suggests that because scarlet fever does not have a vaccine and is also no longer a threat to the population, that means vaccines are not needed to defeat these other diseases. Fact: True, vaccines aren't always necessary to overcome disease and scarlet fever does not have any available vaccinations, but it is no longer a threat due to antibiotics. Vaccines aren't always the best and easiest solution to a disease. That is why vaccines are rigorously tested in clinical trials before being made available to the public. Sometimes vaccines won't work for a certain disease and other solutions will have to be found. Claim: A number of people in the film will claim that vaccines can cause the disease they are meant to prevent in the people receiving them. Fact: Modern vaccines do not cause disease. Vaccines work by priming the immune system. This happens because the vaccine introduces the body to pieces of the pathogen that causes disease. Once cells called macrophages consume the foreign material, they present it on the outside of their cell membrane sort of like a flag. This is called antigen presentation. Other cells will recognize these antigens and this will prime cells called B-cells to produce antibodies. Antibodies recognize that antigen very specifically, they almost never interact with anything else, and they help other cells in the immune system remove the threat. This process of priming the immune system can be done in different ways. There are three main kinds of vaccines to accomplish this. Attenuated: This is a weakened pathogen vaccine. This means the pathogen has been weakened to a state where the body can easily consume it and process its antigens. Attenuated vaccines have some advantages, but many were responsible for adverse side-effects in the early years of vaccine use, especially to immune-compromised patients. This is probably where many of today's misconceptions come from. Attenuated vaccines are still used in certain cases where their safety has been demonstrated, but have been discontinued where they have been shown to be risky. Killed: Killed vaccines, as the name suggests, contain pathogens that have been killed using either heat or chemical means. This means the pathogen can't replicate or function in the human body, but it's pieces will still be processed as foreign material by the immune system. Dr. Scheibner claims in the documentary that bacteria that cause illness by producing toxins will cause illness in killed vaccines because the toxin is not alive and can still cause disease. This is false, however, because bacteria that produce harmful toxins are not used in killed vaccines very often anymore. In the case where harmful toxins might be involved, the next vaccine type can be used. Particle: Particle vaccines take proteins that are unique to a pathogen and deliver them to the body. Every pathogen has a unique genome that produces unique proteins. We select certain proteins and use them in vaccines so that the body can easily process them. If a selected protein is toxic but makes for a good antigen, we can use inactive pieces of that protein called toxoids to elicit the same immune reopens without the toxic effects (the DTaP vaccine, for example). In order for pathogens to cause disease, they need to be able to adhere to a space in our body or attach to cells and then be allowed to grow. These methods of vaccine delivery do not allow for this to happen, nor do they allow for the successful activity of toxins. So vaccines will not cause the disease they are meant to prevent. Claim: Dr. Archie Kalokerinos claims that antibodies, the end product of vaccines, do not offer protection from pathogens. He claims that HIV is an example of this because those who are infected are diagnosed by screening for antibodies against the virus. Fact: It is true that antibodies against HIV in people infected with it are not protected against the disease. In fact, if you ever read about tropical viruses, many were ones that resulted in cases where those infected were diagnosed by testing for antibodies. Many of those diagnosed also died. So what's going on here? The thing to remember about us and pathogens is that is a war. The body has its defenses to hunt down and kill invaders and the invaders have their ways of infiltrating these defenses and taking out every cell they can get to. Both sides are constantly trying to best each other. Our immune systems are very good at dealing with some organisms and not so good at dealing with others. Some pathogens also have become extremely good at defeating our immune system. The example of HIV is actually very simple. HIV stands for human immunodeficiency virus. The virus does what its name suggests, it severely weakens the immune system. So even though there are antibodies against the virus, the immune system is too weak to do anything against the virus. Other factors go into it as well. Some viruses, including HIV and influenza, are extremely efficient at quickly infecting and replicating in human cells. The influenza virus of 1918-1919 could clear a tissue of its cells before white blood cells could even react, all the while releasing thousands of copies of itself per cell it destroys. Another factor is a virus's mutation rate. Out of thousands of viruses released per cell destroyed, there could be hundreds of different versions of one antigen. If the antigen the body uses to recognize the pathogen changes enough, the virus could escape detection. It is a war, and our defenses are never fool-proof against the world of microbes. Claim: Vaccines contain formaldehyde, which is extremely toxic to the body. A parent in the documentary claims that vaccines should not be administered because of this. Fact: The dosage makes the poison. Formaldehyde in vaccines is not present in very high quantities. The reason it is there is to neutralize the pathogen in attenuated vaccines and also to deactivate toxins. With a few injections of relatively low doses of formaldehyde, which we are exposed to in other ways naturally as well, there is no risk for formaldehyde in vaccines. The same goes for other substances that are claimed to be toxic in vaccines. http://www.fda.gov/BiologicsBloodVaccines/SafetyAvailability/VaccineSafety/ucm187810.htm (http://archive.is/IiBmW) Claim: The documentary and others who oppose vaccination commonly claim that early batches of the polio virus were contaminated with SV40, a monkey virus that can cause cancer in humans. Fact: It is true that early polio vaccine batches were contaminated with SV40. Polio can only replicate in cells, so monkey cells were used to get high enough numbers of the virus that vaccines could be made from. This accident resulted in spreading SV40 to millions of US residents between 1955 and 1963. The problem with the claim, however, is that there is no good evidence that the virus causes cancer. http://onlinelibrary.wiley.com/doi/...ionid=4FDAC67D663B49101FB866D4C8C74049.f03t01 (http://archive.is/U7gzC) Claim: This is not discussed in the documentary, but a common claim concerning flu vaccines is that they are dangerous because they cause Guillain-Barre Syndrome, which causes paralysis. Fact: This claim can be traced back to the 1976 swine flu scare. After the death of a young army recruit at Fort Dix, the scene was starting to look eerily like the start of the devastating 1918-1919 pandemic that killed hundreds of millions of people. Everyone was scared and a state of confusion and panic caused rash decisions to be made. Millions of people were quickly immunized against this new strain of flu virus and US President Gerald Ford and his administration encouraged the public to get immunized by stating that any complications caused by the vaccine would be fully compensated by the US government. Despite the fear, the virus flopped and did not spread from Fort Dix. In the aftermath, many people attributed their various ailments to the vaccine in order to receive compensation. Many people did actually contract Guillain-Barre Syndrome and some even died. Although there is debate among epidemiologists about the numbers, the general consensus is that Guillain-Barre Syndrome did seem to be in excess at the time. There is no evidence, however, that there is a link between Guillain-Barre Syndrome and any modern influenza vaccines. http://wwwnc.cdc.gov/eid/article/12/1/05-1007_article.htm (http://archive.is/wwBaX) http://www.cdc.gov/h1n1flu/vaccination/gbs_qa.htm (http://archive.is/7VVMi) There are many myths about vaccines, but the fact is that they have been one of the most important tools for preventing disease over the past century. Diseases that have had vaccines developed for them are preventable, yet some countries are still held down but them. The example I gave earlier in the post about polio in Nigeria is a very real example of what can happen when myths and lies about the science that helped build the living standards we have today are spread and believed. I hope this thread helps dispel those myths and offers a resource for those looking to understand vaccines. Prevention really is the best medicine and that has made vaccines one of our most powerful weapons in our war with microbes. Other resources: http://www.historyofvaccines.org (http://archive.is/JlgnD) http://www.who.int/features/qa/84/en/ (http://archive.is/kKAYY) http://bits.blogs.nytimes.com/2013/...f-contagious-disease-prevented/?emc=eta1&_r=0 (http://archive.is/V9VAj) http://www.nap.edu/catalog.php?record_id=13164 (http://archive.is/xzgbE) The Coming Plague, by Laurie Garret EDIT: Typos and a little more info on toxoid vaccines.