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.
The smallpox vaccine is the first vaccine to have been developed against a contagious disease. In 1796, British physician Edward Jenner demonstrated that an infection with the relatively mild cowpox virus conferred immunity against the deadly smallpox virus. Cowpox served as a natural vaccine until the modern smallpox vaccine emerged in the 20th century. From 1958 to 1977, the World Health Organization (WHO) conducted a global vaccination campaign that eradicated smallpox, making it the only human disease to be eradicated. Although routine smallpox vaccination is no longer performed on the general public, the vaccine is still being produced to guard against bioterrorism, biological warfare, and mpox.
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.
Vaccination and religion have interrelations of varying kinds. No major religion prohibits vaccinations, and some consider it an obligation because of the potential to save lives. However, some people cite religious adherence as a basis for opting to forego vaccinating themselves or their children. Many such objections are pretextual: in Australia, anti-vaccinationists founded the Church of Conscious Living, a "fake church", leading to religious exemptions being removed in that country, and one US pastor was reported to offer vaccine exemptions in exchange for online membership of his church.
A vaccination policy is a health policy adopted in order to prevent the spread of infectious disease. These policies are generally put into place by state or local governments, but may also be set by private facilities, such as workplaces or schools. Many policies have been developed and implemented since vaccines were first made widely available.
Mass vaccination is a public policy effort to vaccinate a large number of people, possibly the entire population of the world or of a country or region, within a short period of time. This policy may be directed during a pandemic, when there is a localized outbreak or scare of a disease for which a vaccine exists, or when a new vaccine is invented.
Health may refer to "a state of complete physical, mental and social well-being and not merely the absence of disease and infirmity.", according to the World Health Organization (WHO). 78.7 was the average life expectancy for individuals at birth in 2017. The highest cause of death for United States citizens is heart disease. Sexually transmitted infections impact the health of approximately 19 million yearly. The two most commonly reported infections include chlamydia and gonorrhea. All 50 states in the U.S. require immunizations for children in order to enroll in public school, but various exemptions are available by state. Immunizations are often compulsory for military enlistment in the United States.
Jacobson v. Massachusetts, 197 U.S. 11 (1905), was a United States Supreme Court case in which the Court upheld the authority of states to enforce compulsory vaccination laws. The Court's decision articulated the view that individual liberty is not absolute and is subject to the police power of the state. Jacobson has been invoked in numerous other Supreme Court cases as an example of a baseline exercise of the police power.
The 1947 New York City smallpox outbreak occurred in March 1947 and was declared ended on April 24, 1947. The outbreak marked the largest mass vaccination effort ever conducted for smallpox in America. Within three weeks of the discovery of the outbreak, the U.S. Public Health Service, in conjunction with New York City health officials, had procured the smallpox vaccine and inoculated over 6,350,000 adults and children. Of that number, 5,000,000 had been vaccinated within the first two weeks. The rapid response was credited with limiting the outbreak to 12 people, 10 of whom recovered, while 2 died.
California Senate Bill 277 (SB277) is a California law that removed personal belief as a reason for an exemption from the vaccination requirements for entry to private or public elementary or secondary schools in California, as well as day care centers. The final version of the bill was enacted by the California Legislature in 2015 and was signed into law by Governor Jerry Brown on June 30, 2015.
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 reality-based view of anatomy. "Straight" chiropractors are very likely to be anti-vaccination, but all chiropractic training tends to reduce acceptance of vaccines.
Vaccination policy of the United States is the subset of U.S. federal health policy that deals with immunization against infectious disease. It is decided at various levels of the government, including the individual states. This policy has been developed over the approximately two centuries since the invention of vaccination with the purpose of eradicating disease from the U.S. population, or creating a herd immunity. Policies intended to encourage vaccination impact numerous areas of law, including regulation of vaccine safety, funding of vaccination programs, vaccine mandates, adverse event reporting requirements, and compensation for injuries asserted to be associated with vaccination.
Phillips v. City of New York, 775 F.3d 538, cert. denied, 136 S. Ct. 104 (2015), was a 2015 decision of the United States Court of Appeals for the Second Circuit addressing vaccination mandates and exemptions from them in New York City. The court concluded that it was within the constitutional police power of the state to mandate vaccination, and that religious exemptions were not constitutionally required. Therefore, even though the state did permit religious exemptions, it was free to provide them with limitations including the exclusion of exempted children from school during an outbreak of the disease, and requiring applicants to demonstrate the sincerity of their religious objection in order to receive an exemption.
Caviezel v. Great Neck Public Schools, 500 Fed. Appx. 16 (2012), is a decision of the United States Court of Appeals for the Second Circuit upholding the denial of a religious exemption to mandatory vaccination sought by a parent who claimed to adhere to a non-denominational religious view without a formal doctrine.
Vaccination requirements for international travel are the aspect of vaccination policy that concerns the movement of people across borders. Countries around the world require travellers departing to other countries, or arriving from other countries, to be vaccinated against certain infectious diseases in order to prevent epidemics. At border checks, these travellers are required to show proof of vaccination against specific diseases; the most widely used vaccination record is the International Certificate of Vaccination or Prophylaxis. Some countries require information about a passenger's vaccination status in a passenger locator form.
Klaassen v. Indiana University, was a 2021 United States federal court case in which students attending Indiana University challenged the institution's COVID-19 vaccine mandate set to go into effect in September 2021. A motion for preliminary injunction was denied by Judge Damon R. Leichty on July 18, 2021. On August 2, 2021, the United States Court of Appeals for the Seventh Circuit also denied a motion to enjoin the mandate while Leichty's ruling was appealed. On August 12, 2021, Justice Amy Coney Barrett denied relief to the petitioners, allowing the vaccination mandate to go into effect. The case is named for lead plaintiff Ryan Klassen of Noble County, Indiana.
Over the course of the COVID-19 pandemic, COVID-19 vaccine mandates have been enacted by numerous states and municipalities in the United States, and also by private entities. In September 2021, President Joe Biden announced that the federal government would take steps to mandate COVID-19 vaccination for certain entities under the authority of the federal government or federal agencies. Most federal mandates thus imposed were either overturned through litigation, or withdrawn by the administration, although a mandate on health care workers in institutions receiving Medicare and Medicaid funds was upheld. All federal mandates were lifted when the national emergency was declared to have ended in May 2023. A small number of states have gone in the opposite direction, through executive orders or legislation designed to limit vaccination mandates.
The Biden administration COVID-19 action plan, also called the Path out of the Pandemic, is a substantial increase in the use of vaccination mandates as part of the U.S. federal government response to the COVID-19 pandemic announced by President Joe Biden on September 9, 2021, to be carried out by officials in the Biden administration. The plan included various announced prospective efforts, as well as the issuance of several executive orders.
National Federation of Independent Business v. Department of Labor, Occupational Safety and Health Administration, 595 U.S. ___ (2022), is a Supreme Court of the United States case before the Court on an application for a stay of the Occupational Safety and Health Administration's COVID-19 vaccination or test mandate. On January 13, 2022, the Supreme Court ordered a stay of the mandate.
