This is a list of vaccine-related topics.
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins. The agent stimulates the body's immune system to recognize the agent as foreign, destroy it, and "remember" it, so that the immune system can more easily recognize and destroy any of these microorganisms that it later encounters. [1]
Bacillus Calmette–Guérin (BCG) vaccine is a vaccine primarily used against tuberculosis (TB). It is named after its inventors Albert Calmette and Camille Guérin. In countries where tuberculosis or leprosy is common, one dose is recommended in healthy babies as soon after birth as possible. In areas where tuberculosis is not common, only children at high risk are typically immunized, while suspected cases of tuberculosis are individually tested for and treated. Adults who do not have tuberculosis and have not been previously immunized, but are frequently exposed, may be immunized, as well. BCG also has some effectiveness against Buruli ulcer infection and other nontuberculous mycobacterial infections. Additionally, it is sometimes used as part of the treatment of bladder cancer.
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 recognize further and destroy any of the microorganisms associated with that agent that it may encounter in the future.
Herd immunity is a form of indirect protection that applies only to contagious diseases. It occurs when a sufficient percentage of a population has become immune to an infection, whether through previous infections or vaccination, thereby reducing the likelihood of infection for individuals who lack immunity.
An HIV vaccine is a potential vaccine that could be either a preventive vaccine or a therapeutic vaccine, which means it would either protect individuals from being infected with HIV or treat HIV-infected individuals.
Polio vaccines are vaccines used to prevent poliomyelitis (polio). Two types are used: an inactivated poliovirus given by injection (IPV) and a weakened poliovirus given by mouth (OPV). The World Health Organization (WHO) recommends all children be fully vaccinated against polio. The two vaccines have eliminated polio from most of the world, and reduced the number of cases reported each year from an estimated 350,000 in 1988 to 33 in 2018.
Varicella zoster virus (VZV), also known as human herpesvirus 3 or Human alphaherpesvirus 3 (taxonomically), is one of nine known herpes viruses that can infect humans. It causes chickenpox (varicella) commonly affecting children and young adults, and shingles in adults but rarely in children. VZV infections are species-specific to humans. The virus can survive in external environments for a few hours.
Influenza vaccines, also known as flu shots, are vaccines that protect against infection by influenza viruses. New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. The United States Centers for Disease Control and Prevention (CDC) estimates that vaccination against influenza reduces sickness, medical visits, hospitalizations, and deaths. Immunized workers who do catch the flu return to work half a day sooner on average. Vaccine effectiveness in those over 65 years old remains uncertain due to a lack of high-quality research.
Anthrax vaccines are vaccines to prevent the livestock and human disease anthrax, caused by the bacterium Bacillus anthracis.
An attenuated vaccine is a vaccine created by reducing the virulence of a pathogen, but still keeping it viable. Attenuation takes an infectious agent and alters it so that it becomes harmless or less virulent. These vaccines contrast to those produced by "killing" the pathogen.
Hepatitis B vaccine is a vaccine that prevents hepatitis B. The first dose is recommended within 24 hours of birth with either two or three more doses given after that. This includes those with poor immune function such as from HIV/AIDS and those born premature. It is also recommended that health-care workers be vaccinated. In healthy people, routine immunization results in more than 95% of people being protected.
The rabies vaccine is a vaccine used to prevent rabies. There are several rabies vaccines available that are both safe and effective. They can be used to prevent rabies before, and, for a period of time, after exposure to the rabies virus, which is commonly caused by a dog bite or a bat bite.
Yellow fever vaccine is a vaccine that protects against yellow fever. Yellow fever is a viral infection that occurs in Africa and South America. Most people begin to develop immunity within ten days of vaccination and 99% are protected within one month, and this appears to be lifelong. The vaccine can be used to control outbreaks of disease. It is given either by injection into a muscle or just under the skin.
A subunit vaccine is a vaccine that contains purified parts of the pathogen that are antigenic, or necessary to elicit a protective immune response. Subunit vaccine can be made from dissembled viral particles in cell culture or recombinant DNA expression, in which case it is a recombinant subunit vaccine.
Vaccinia immune globulin (VIG) is made from the pooled blood of individuals who have been inoculated with the smallpox vaccine. The antibodies these individuals developed in response to the smallpox vaccine are removed and purified. This results in VIG. It can be administered intravenously. It is used to treat individuals who have developed progressive vaccinia after smallpox vaccination.
Ebola vaccines are vaccines either approved or in development to prevent Ebola. As of 2022, there are only vaccines against the Zaire ebolavirus. The first vaccine to be approved in the United States was rVSV-ZEBOV in December 2019. It had been used extensively in the Kivu Ebola epidemic under a compassionate use protocol. During the early 21st century, several vaccine candidates displayed efficacy to protect nonhuman primates against lethal infection.
A universal flu vaccine is a flu vaccine that is effective against all influenza strains regardless of the virus sub type, antigenic drift or antigenic shift. Hence it should not require modification from year to year. As of 2021 no universal flu vaccine had been approved for general use, several were in development, and one was in clinical trial.
Intrastructural help (ISH) is where T and B cells cooperate to help or suppress an immune response gene. ISH has proven effective for the treatment of influenza, rabies related lyssavirus, hepatitis B, and the HIV virus. This process was used in 1979 to observe that T cells specific to the influenza virus could promote the stimulation of hemagglutinin specific B cells and elicit an effective humoral immune response. It was later applied to the lyssavirus and was shown to protect raccoons from lethal challenge. The ISH principle is especially beneficial because relatively invariable structural antigens can be used for the priming of T-cells to induce humoral immune response against variable surface antigens. Thus, the approach has also transferred well for the treatment of hepatitis B and HIV.
A viral vector vaccine is a vaccine that uses a viral vector to deliver genetic material (DNA) that can be transcribed by the recipient's host cells as mRNA coding for a desired protein, or antigen, to elicit an immune response. As of April 2021, six viral vector vaccines, four COVID-19 vaccines and two Ebola vaccines, have been authorized for use in humans.