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.
Measles is a highly contagious, vaccine-preventable infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than 40 °C (104 °F), cough, runny nose, and inflamed eyes. Small white spots known as Koplik's spots may form inside the mouth two or three days after the start of symptoms. A red, flat rash which usually starts on the face and then spreads to the rest of the body typically begins three to five days after the start of symptoms. Common complications include diarrhea, middle ear infection (7%), and pneumonia (6%). These occur in part due to measles-induced immunosuppression. Less commonly seizures, blindness, or inflammation of the brain may occur. Other names include morbilli, rubeola, red measles, and English measles. Both rubella, also known as German measles, and roseola are different diseases caused by unrelated viruses.
The Pasteur Institute is a French non-profit private foundation dedicated to the study of biology, micro-organisms, diseases, and vaccines. It is named after Louis Pasteur, who invented pasteurization and vaccines for anthrax and rabies. The institute was founded on 4 June 1887 and inaugurated on 14 November 1888.
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.
The Global Burden of Disease Study (GBD) is a comprehensive regional and global research program of disease burden that assesses mortality and disability from major diseases, injuries, and risk factors. GBD is a collaboration of over 3600 researchers from 145 countries. Under principal investigator Christopher J.L. Murray, GBD is based in the Institute for Health Metrics and Evaluation (IHME) at the University of Washington and funded by the Bill and Melinda Gates Foundation.
Vitamin A deficiency (VAD) or hypovitaminosis A is a lack of vitamin A in blood and tissues. It is common in poorer countries, especially among children and women of reproductive age, but is rarely seen in more developed countries. Nyctalopia is one of the first signs of VAD, as the vitamin has a major role in phototransduction; but it is also the first symptom that is reversed when vitamin A is consumed again. Xerophthalmia, keratomalacia, and complete blindness can follow if the deficiency is more severe.
In immunology, passive immunity is the transfer of active humoral immunity of ready-made antibodies. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and it can also be induced artificially, when high levels of antibodies specific to a pathogen or toxin are transferred to non-immune persons through blood products that contain antibodies, such as in immunoglobulin therapy or antiserum therapy. Passive immunization is used when there is a high risk of infection and insufficient time for the body to develop its own immune response, or to reduce the symptoms of ongoing or immunosuppressive diseases. Passive immunization can be provided when people cannot synthesize antibodies, and when they have been exposed to a disease that they do not have immunity against.
Statens Serum Institut, is a Danish sector research institute located on the island of Amager in Copenhagen. Its purpose is to combat and prevent infectious diseases, congenital disorders, and threats from weapons of mass destruction.
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 discredited former doctor 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.
In epidemiology, the excess deaths or excess mortality is a measure of the increase in the number deaths during a time period and/or in a certain group, as compared to the expected value or statistical trend during a reference period or in a reference population. It may typically be measured in percentage points, or in number of deaths per time unit.
The eradication of infectious diseases is the reduction of the prevalence of an infectious disease in the global host population to zero.
The Demographic and Health Surveys (DHS) Program is responsible for collecting and disseminating accurate, nationally representative data on health and population in developing countries. The project is implemented by ICF International and is funded by the United States Agency for International Development (USAID) with contributions from other donors such as UNICEF, UNFPA, WHO, and UNAIDS.
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 the 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 decreases. 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 International Association of National Public Health Institutes (IANPHI) is an international umbrella organization of national public health institutes (NPHIs), public health government agencies working to improve national disease prevention and response. IANPHI is made up of 100+ members, located in more than 90 countries. An important goal of IANPHI is to improve health outcomes by strengthening NPHIs or supporting countries in creating new NPHIs.
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.
The WHO's estimate of life expectancy for a female child born in Guinea-Bissau in 2008 was 49 years, and 47 years for a boy. in 2016 life expectancy had improved to 58 for men and 61 for women.
Preben Christian Alexander von Magnus was a Danish virologist who is known for his research on influenza, polio vaccination and monkeypox. He gave his name to the Von Magnus phenomenon.
Non-specific effects of vaccines are effects which go beyond the specific protective effects against the targeted diseases. Non-specific effects can be strongly beneficial by increasing protection against non-targeted infections. This has been shown with two live attenuated vaccines, BCG vaccine and measles vaccine, through multiple randomized controlled trials. Theoretically, non-specific effects of vaccines may be detrimental, increasing overall mortality despite providing protection against the target diseases. Although observational studies suggest that diphtheria-tetanus-pertussis vaccine (DTP) may be highly detrimental, these studies are at high risk of bias and have failed to replicate when conducted by independent groups.
Peter Aaby is trained as an anthropologist but also holds a doctoral degree in medicine. In 1978, Peter Aaby established the Bandim Health Project, a Health and Demographic Surveillance System site in Guinea-Bissau in West Africa, which he has run ever since. In 2000, Peter Aaby was awarded the Novo Nordisk Prize, the most important Danish award within health research.
Amabélia Rodrigues is a Bissau-Guinean epidemiologist. She is the first female director of the National Institute of Public Health of Guinea-Bissau. She is also the lead research coordinator of the Bandim Health Project.
