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. However, some diseases, such as measles outbreaks in America, have seen rising cases due to relatively low vaccination rates in the 2010s – attributed, in part, to vaccine hesitancy. According to the World Health Organization, vaccination prevents 3.5–5 million deaths per year.
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future.
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. 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.
Generation Rescue is a nonprofit organization that advocates the scientifically disproven view that autism and related disorders are primarily caused by environmental factors, particularly vaccines. The organization was established in 2005 by Lisa and J.B. Handley. Today, Generation Rescue is known as a platform for Jenny McCarthy's autism related anti-vaccine advocacy.
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 claimed to link the vaccine to colitis and autism spectrum disorders. The paper was retracted in 2010 but is still cited by anti-vaccinationists.
Andrew Jeremy Wakefield is a British anti-vaccine activist, former physician, and discredited academic who was struck off the medical register for his involvement in The Lancet MMR autism fraud, a 1998 study that falsely claimed a link between the measles, mumps, and rubella (MMR) vaccine and autism. He has subsequently become known for anti-vaccination activism. Publicity around the 1998 study caused a sharp decline in vaccination uptake, leading to a number of outbreaks of measles around the world. He was a surgeon on the liver transplant programme at the Royal Free Hospital in London and became senior lecturer and honorary consultant in experimental gastroenterology at the Royal Free and University College School of Medicine. He resigned from his positions there in 2001, "by mutual agreement", then moved to the United States. In 2004, Wakefield co-founded and began working at the Thoughtful House research center in Austin, Texas, serving as executive director there until February 2010, when he resigned in the wake of findings against him by the British General Medical Council.
Warnings About Vaccination Expectations NZ (WAVESnz), formerly the Immunisation Awareness Society (IAS), is a New Zealand anti-vaccination lobby group.
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.
An alternative vaccination schedule is a vaccination schedule differing from the schedule endorsed by the Advisory Committee on Immunization Practices (ACIP). These schedules may be either written or ad hoc, and have not been tested for their safety or efficacy. Proponents of such schedules aim to reduce the risk of adverse effects they believe to be caused by vaccine components, such as "immune system overload" that is argued to be caused by exposure to multiple antigens. Parents who adopt these schedules tend to do so because they are concerned about the potential risks of vaccination, rather than because they are unaware of the significance of vaccination's benefits.
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.
Children's Health Defense is an American 501(c)(3) nonprofit activist group mainly known for anti-vaccine propaganda and has been identified as one of the main sources of misinformation on vaccines. Founded under the name World Mercury Project in 2011, it is chaired by Robert F. Kennedy Jr. The group has been campaigning against various public health programs, such as vaccination and fluoridation of drinking water. The group has been contributing to vaccine hesitancy in the United States, encouraging citizens and legislators to support anti-vaccine regulations and legislation. Arguments against vaccination are contradicted by overwhelming scientific consensus about the safety and effectiveness of vaccines.
Vaccine Choice Canada (VCC) is Canada's main anti-vaccination group. It was founded in the 1980s under the name Vaccination Risk Awareness Network (VRAN) and adopted its current name in 2014. The group has been contributing to vaccine hesitancy in Canada, encouraging citizens to forgo immunization and legislators to support anti-vaccine regulations and legislation.
Del Matthew Bigtree is an American television and film producer as well as CEO of the anti-vaccination group Informed Consent Action Network. He produced the film Vaxxed: From Cover-Up to Catastrophe, based on the discredited opinions of Andrew Wakefield and alleges an unsubstantiated connection between vaccines and autism.
The Informed Consent Action Network (ICAN) is one of the main anti-vaccination groups in the United States. Founded in 2016 by Del Bigtree, it spreads misinformation about the risks of vaccines and contributes to vaccine hesitancy, which has been identified by the World Health Organization as one of the top ten global health threats of 2019. Arguments against vaccination are contradicted by overwhelming scientific consensus about the safety and effectiveness of vaccines.
The 2019 Samoa measles outbreak began in September 2019. As of 6 January 2020, there were over 5,700 cases of measles and 83 deaths, out of a Samoan population of 200,874. Over three percent of the population were infected. The cause of the outbreak was attributed to decreased vaccination rates, from 74% in 2017 to 31–34% in 2018, even though nearby islands had rates near 99%.
Taylor Winterstein is an Australian-Samoan online influencer known for her public anti-vaccination stance. Winterstein has been heavily criticised in several South Pacific, and Australasian countries for her anti-vaccination rhetoric and her seminars have been called "irresponsible" by the Australian Medical Association and a "public health threat" by the Samoan Ministry of Health. She claims she has not encouraged non-vaccination, rather, "informed consent" and "freedom of choice".
The Stop Mandatory Vaccination website and associated Facebook group are some of the major hubs of the American anti-vaccination movement. It was established by anti-vaccination activist Larry Cook in 2015.
Misinformation related to immunization 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. Intentional spreading of false information and conspiracy theories have also been propagated by the general public and celebrities. Misinformation related to vaccination fuels vaccine hesitancy and thereby results in disease outbreaks. Although opposition to vaccination has existed for centuries, the internet and social media have recently facilitated the spread of vaccine-related misinformation. Unsubstantiated safety concerns related to vaccines are often presented on the internet as scientific information.
Medical Racism: The New Apartheid is a 2021 video production that promotes conspiracy theories about COVID-19 vaccines. Distributed by the anti-vaccination group Children's Health Defense, it alleges the COVID-19 vaccination efforts are a cover to conduct experiments on African American and Latin communities. Public health communication experts say the video presents actual injustices committed against African Americans in the past in order to make debunked anti-vaccination claims more believable.
The Disneyland measles outbreak began at the Disneyland Resort, California, in December 2014, and spread to seven states in the United States, Mexico, and Canada, before it was declared over in mid-April 2015.
