Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating the body's adaptive immunity, they help prevent sickness from an infectious disease. When a sufficiently large percentage of a population has been vaccinated, herd immunity results. Herd immunity protects those who may be immunocompromised and cannot get a vaccine because even a weakened version would harm them. The effectiveness of vaccination has been widely studied and verified. Vaccination is the most effective method of preventing infectious diseases; widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the elimination of diseases such as polio and tetanus from much of the world. According to the World Health Organization (WHO), vaccination prevents 3.5–5 million deaths per year. A WHO-funded study by The Lancet estimates that, during the 50-year period starting in 1974, vaccination prevented 154 million deaths, including 146 million among children under age 5. However, some diseases have seen rising cases due to relatively low vaccination rates attributable partly to vaccine hesitancy.
Vaccine hesitancy is a delay in acceptance, or refusal, of vaccines despite the availability of vaccine services and supporting evidence. The term covers refusals to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain about their use, or using certain vaccines but not others. Although adverse effects associated with vaccines are occasionally observed, the scientific consensus that vaccines are generally safe and effective is overwhelming. Vaccine hesitancy often results in disease outbreaks and deaths from vaccine-preventable diseases. Therefore, the World Health Organization characterizes vaccine hesitancy as one of the top ten global health threats.
The Wistar Institute is an independent, nonprofit research institution in biomedical science with special focuses in oncology, immunology, infectious disease, and vaccine research. Located on Spruce Street in the University City section of Philadelphia, Wistar was founded in 1892 as a nonprofit institution to focus on biomedical research and training.
Concerns about thiomersal and vaccines are commonly expressed by anti-vaccine activists. Claims relating to the safety of thiomersal, a mercury-based preservative used in vaccines, are refuted, but still subject to fearmongering, notably claims it could cause neurological disorders such as autism, leading to its removal from most vaccines in the US childhood schedule. This had no effect on the rates of diagnosis of pervasive developmental defects, including autism. Extensive scientific research shows no credible evidence linking thiomersal to such conditions.
A vaccine adverse event (VAE), sometimes referred to as a vaccine injury, is an adverse event believed to have been caused by vaccination. The World Health Organization (WHO) refers to Adverse Events Following Immunization (AEFI).
Many causes of autism, including environmental and genetic factors, have been recognized or proposed, but understanding of the theory of causation of autism is incomplete. Attempts have been made to incorporate the known genetic and environmental causes into a comprehensive causative framework. ASD is a neurodevelopmental disorder marked by impairments in communicative ability and social interaction, as well as restricted and repetitive behaviors, interests, or activities not suitable for the individual's developmental stage. The severity of symptoms and functional impairment vary between individuals.
Paul Allan Offit is an American pediatrician specializing in infectious diseases, vaccines, immunology, and virology. He is the co-inventor of a rotavirus vaccine. Offit is the Maurice R. Hilleman Professor of Vaccinology, professor of pediatrics at the Perelman School of Medicine at the University of Pennsylvania, former chief of the Division of Infectious Diseases (1992–2014), and the director of the Vaccine Education Center at the Children's Hospital of Philadelphia.
Brian S. Hooker a biologist and chemist who was department chair and Professor Emeritus of Biology at Simpson University. He is known for promoting the false claim that vaccines cause autism.
Claims of a link between the MMR vaccine and autism have been extensively investigated and found to be false. The link was first suggested in the early 1990s and came to public notice largely as a result of the 1998 Lancet MMR autism fraud, characterised as "perhaps the most damaging medical hoax of the last 100 years". The fraudulent research paper, authored by Andrew Wakefield and published in The Lancet, falsely claimed the vaccine was linked to colitis and autism spectrum disorders. The paper was retracted in 2010 but is still cited by anti-vaccine activists.
Throughout its history, chiropractic has been the subject of internal and external controversy and criticism. According to magnetic healer Daniel D. Palmer, the founder of chiropractic, "vertebral subluxation" was the sole cause of all diseases and manipulation was the cure for all disease. Internal divisions between "straights," who adhere strictly to Palmer’s original philosophy, and "mixers," who incorporate broader medical practices, have further complicated the profession’s identity. A 2003 profession-wide survey found "most chiropractors still hold views of Innate Intelligence and of the cause and cure of disease consistent with those of the Palmers". A critical evaluation stated "Chiropractic is rooted in mystical concepts. This led to an internal conflict within the chiropractic profession, which continues today." Chiropractors, including D.D. Palmer, were jailed for practicing medicine without a license. D.D. Palmer considered establishing chiropractic as a religion to resolve this problem. For most of its existence, chiropractic has battled with mainstream medicine, sustained by antiscientific and pseudoscientific ideas such as vertebral subluxation.
Andrew Jeremy Wakefield is a British fraudster, discredited academic, anti-vaccine activist, and former physician.
David Henry Gorski is an American surgical oncologist and professor of surgery at Wayne State University School of Medicine. He specializes in breast cancer surgery at the Karmanos Cancer Institute. Gorski is an outspoken skeptic and critic of alternative medicine and the anti-vaccination movement. He writes as Orac at Respectful Insolence and as himself at Science-Based Medicine, where he is the managing editor.
Robert William Sears, known as Dr. Bob, is an American pediatrician from Capistrano Beach, California, noted for his unorthodox and dangerous views on childhood vaccination. While Sears acknowledges the efficacy of vaccines—for instance, he supports the claim that Chicken pox, measles, whooping cough, polio, diphtheria have all disappeared because of vaccines—he has proposed alternative vaccination schedules that depart from accepted medical recommendations. His proposals have enjoyed celebrity endorsement but are not supported by medical evidence and have contributed to dangerous under-vaccination in the national child population. While he denies being anti-vaccine, Sears has been described by many as anti-vaccine and as a vaccine delayer.
Herman Hugh Fudenberg was an American clinical immunologist and the sole identified member of the Neuro Immuno Therapeutics Research Foundation (NITRF).
Texans for Vaccine Choice (TFVC) is an anti-vaccine Facebook group turned political action committee in Texas which advocates for personal belief exemptions to vaccination requirements, based on "a collection of fake news, half- truths, and conspiracy theories". Andrew Wakefield, the disgraced former medical researcher and originator of the MMR autism hoax, and infectious disease specialist Peter Hotez, both describe TFVC's lobbying as very effective, with the rate of Texas students opting out of at least one vaccine at least doubling in around five years and over 50,000 Texas schoolchildren not being vaccinated.
The Lancet MMR autism fraud centered on the publication in February 1998 of a fraudulent research paper titled "Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children" in the Lancet. The paper, authored by now discredited and deregistered Andrew Wakefield, and twelve coauthors, falsely claimed causative links between the measles, mumps, and rubella (MMR) vaccine and colitis and between colitis and autism. The fraud involved data selection, data manipulation, and two undisclosed conflicts of interest. It was exposed in a lengthy Sunday Times investigation by reporter Brian Deer, resulting in the paper's retraction in February 2010 and Wakefield being struck off the UK medical register three months later. Wakefield reportedly stood to earn up to US$43 million per year selling diagnostic kits for a non-existent syndrome he claimed to have discovered. He also held a patent to a rival vaccine at the time, and he had been employed by a lawyer representing parents in lawsuits against vaccine producers.
Anti-vaccinationism in chiropractic is widespread, but there are notable differences within the trade. Chiropractic is a form of alternative medicine founded on the idea that all disease is caused by disruption of the flow of "innate" in the spine, by so-called vertebral subluxations – a pseudoscientific concept. Over time chiropractic has divided into "straights" who adhere to the subluxation theory and "mixers" who adhere more closely to a scientifically-based view of anatomy. "Straight" chiropractors are very likely to be anti-vaccination, but all chiropractic training tends to reduce acceptance of vaccines.
Extensive investigation into vaccines and autism spectrum disorder has shown that there is no relationship between the two, causal or otherwise, and that vaccine ingredients do not cause autism. The American scientist Peter Hotez researched the growth of the false claim and concluded that its spread originated with Andrew Wakefield's fraudulent 1998 paper, and that no prior paper supports a link.
Misinformation related to immunization and the use of vaccines circulates in mass media and social media in spite of the fact that there is no serious hesitancy or debate within mainstream medical and scientific circles about the benefits of vaccination. Unsubstantiated safety concerns related to vaccines are often presented on the internet as being scientific information. A large proportion of internet sources on the topic are mostly inaccurate which can lead people searching for information to form misconceptions relating to vaccines.
Anti-vaccine activism, which collectively constitutes the "anti-vax" movement, is a set of organized activities proclaiming opposition to vaccination, and these collaborating networks have often fought to increase vaccine hesitancy by disseminating vaccine-based misinformation and/or forms of active disinformation. As a social movement, it has utilized multiple tools both within traditional news media and also through various forms of online communication. Activists have primarily focused on issues surrounding children, with vaccination of the young receiving pushback, and they have sought to expand beyond niche subgroups into national political debates.
