The Centers for Disease Control and Prevention (CDC) is the national public health agency of the United States. It is a United States federal agency under the Department of Health and Human Services, and is headquartered in Atlanta, Georgia.
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 MMR vaccine is a vaccine against measles, mumps, and rubella, abbreviated as MMR. The first dose is generally given to children around 9 months to 15 months of age, with a second dose at 15 months to 6 years of age, with at least four weeks between the doses. After two doses, 97% of people are protected against measles, 88% against mumps, and at least 97% against rubella. The vaccine is also recommended for those who do not have evidence of immunity, those with well-controlled HIV/AIDS, and within 72 hours of exposure to measles among those who are incompletely immunized. It is given by injection.
Thiomersal (INN), or thimerosal, is an organomercury compound. It is a well-established antiseptic and antifungal agent.
The Vaccine Adverse Event Reporting System (VAERS) is a United States program for vaccine safety, co-managed by the U.S. Centers for Disease Control and Prevention (CDC) and the Food and Drug Administration (FDA). VAERS is a postmarketing surveillance program, collecting information about adverse events that occur after administration of vaccines to ascertain whether the risk–benefit ratio is high enough to justify continued use of any particular vaccine.
The 2000 Simpsonwood CDC conference was a two-day meeting convened in June 2000 by the Centers for Disease Control and Prevention (CDC), held at the Simpsonwood Methodist retreat and conference center in Norcross, Georgia. The key event at the conference was the presentation of data from the Vaccine Safety Datalink examining the possibility of a link between the mercury compound thimerosol in vaccines and neurological problems in children who had received those vaccines.
Thiomersal is a mercury compound which is used as a preservative in some vaccines. Anti-vaccination activists promoting the incorrect claim that vaccination causes autism have asserted that the mercury in thiomersal is the cause. There is no scientific evidence to support this claim. The idea that thiomersal in vaccines might have detrimental effects originated with anti-vaccination activists and was sustained by them and especially through the action of plaintiffs' lawyers.
A vaccine adverse event (VAE), sometimes referred to as a vaccine injury, is an adverse event caused by vaccination. The World Health Organization (WHO) knows VAEs as Adverse Events Following Immunization (AEFI).
Neal A. Halsey is an American pediatrician, with sub-specialty training in infectious diseases, international health and epidemiology. Halsey is a professor emeritus of international health and director emeritus of the Institute for Vaccine Safety at the Johns Hopkins Bloomberg School of Public Health, in Baltimore, Maryland. He had a joint appointment in the Department of Pediatrics at the Johns Hopkins School of Medicine and serves as co-director of the Center for Disease Studies and Control in Guatemala.
The MMRV vaccine combines the attenuated virus MMR vaccine with the addition of the chickenpox vaccine or varicella vaccine. The MMRV vaccine is typically given to children between one and two years of age.
Mumps vaccines are vaccines which prevent mumps. When given to a majority of the population they decrease complications at the population level. Effectiveness when 90% of a population is vaccinated is estimated at 85%. Two doses are required for long term prevention. The initial dose is recommended between 12 and 18 months of age. The second dose is then typically given between two years and six years of age. Usage after exposure in those not already immune may be useful.
Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox. One dose of vaccine prevents 95% of moderate disease and 100% of severe disease. Two doses of vaccine are more effective than one. If given to those who are not immune within five days of exposure to chickenpox it prevents most cases of disease. Vaccinating a large portion of the population also protects those who are not vaccinated. It is given by injection just under the skin. Another vaccine, known as zoster vaccine, is used to prevent diseases caused by the same virus – the varicella zoster virus.
NmVac4-A/C/Y/W-135 is the commercial name of the polysaccharide vaccine against the bacterium that causes meningococcal meningitis. The product, by JN-International Medical Corporation, is designed and formulated to be used in developing countries for protecting populations during meningitis disease epidemics.
Measles vaccine protects against becoming infected with measles. Nearly all of those who do not develop immunity after a single dose develop it after a second dose. When rate of vaccination within a population is greater than 92%, outbreaks of measles typically no longer occur; however, they may occur again if the rate of vaccination decrease. The vaccine's effectiveness lasts many years. It is unclear if it becomes less effective over time. The vaccine may also protect against measles if given within a couple of days after exposure to measles.
The Vaccines for Children Program (VFC) is a federally funded program in the United States providing no-cost vaccines to children who lack health insurance or who otherwise cannot afford the cost of the vaccination. The VFC program was created by the Omnibus Budget Reconciliation Act of 1993 and is required to be a new entitlement of each state's Medicaid plan under section 1928 of the Social Security Act. The program was officially implemented in October 1994 and serves eligible children in all U.S. states, as well as the Commonwealth of Puerto Rico, the U.S. Virgin Islands, American Samoa, Guam, and the Commonwealth of the Northern Mariana Islands.
Frank DeStefano FACPM is a medical epidemiologist and researcher at the Centers for Disease Control and Prevention, where he is director of the Immunization Safety Office.
Michael E. Pichichero is an American physician who is the Director of the Rochester General Hospital Research Institute, a Research Professor at Rochester Institute of Technology and a clinical professor in the Department of Pediatrics at the University of Rochester Medical Center. He is the author of a number of scientific studies regarding the safety of thimerosal as a preservative in vaccines.
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. Delayed vaccination schedules have been shown to lead to an increase in breakthrough infections without any benefit in lower side effect profiles.
Extensive investigation into vaccines and autism spectrum disorder has shown that there is no relationship between the two, causal or otherwise, and that the vaccine ingredients do not cause autism. Vaccinologist Peter Hotez researched the growth of the false claim and concluded that its spread originated with Andrew Wakefield's fraudulent 1998 paper, with no prior paper supporting a link.
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.