Vaccines: Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases.Vaccines, Inactivated: Vaccines in which the infectious microbial nucleic acid components have been destroyed by chemical or physical treatment (e.g., formalin, beta-propiolactone, gamma radiation) without affecting the antigenicity or immunogenicity of the viral coat or bacterial outer membrane proteins.Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Vaccines, DNA: Recombinant DNA vectors encoding antigens administered for the prevention or treatment of disease. The host cells take up the DNA, express the antigen, and present it to the immune system in a manner similar to that which would occur during natural infection. This induces humoral and cellular immune responses against the encoded antigens. The vector is called naked DNA because there is no need for complex formulations or delivery agents; the plasmid is injected in saline or other buffers.Vaccines, Combined: Two or more vaccines in a single dosage form.Bacterial Vaccines: Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.AIDS Vaccines: Vaccines or candidate vaccines containing inactivated HIV or some of its component antigens and designed to prevent or treat AIDS. Some vaccines containing antigens are recombinantly produced.Vaccines, Subunit: Vaccines consisting of one or more antigens that stimulate a strong immune response. They are purified from microorganisms or produced by recombinant DNA techniques, or they can be chemically synthesized peptides.Vaccines, Conjugate: Semisynthetic vaccines consisting of polysaccharide antigens from microorganisms attached to protein carrier molecules. The carrier protein is recognized by macrophages and T-cells thus enhancing immunity. Conjugate vaccines induce antibody formation in people not responsive to polysaccharide alone, induce higher levels of antibody, and show a booster response on repeated injection.Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Malaria Vaccines: Vaccines made from antigens arising from any of the four strains of Plasmodium which cause malaria in humans, or from P. berghei which causes malaria in rodents.Papillomavirus Vaccines: Vaccines or candidate vaccines used to prevent PAPILLOMAVIRUS INFECTIONS. Human vaccines are intended to reduce the incidence of UTERINE CERVICAL NEOPLASMS, so they are sometimes considered a type of CANCER VACCINES. They are often composed of CAPSID PROTEINS, especially L1 protein, from various types of ALPHAPAPILLOMAVIRUS.Vaccines, Attenuated: Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.Meningococcal Vaccines: Vaccines or candidate vaccines used to prevent infection with NEISSERIA MENINGITIDIS.Measles Vaccine: A live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had measles or been immunized with live measles vaccine and have no serum antibodies against measles. Children are usually immunized with measles-mumps-rubella combination vaccine. (From Dorland, 28th ed)Hepatitis B Vaccines: Vaccines or candidate vaccines containing inactivated hepatitis B or some of its component antigens and designed to prevent hepatitis B. Some vaccines may be recombinantly produced.Pertussis Vaccine: A suspension of killed Bordetella pertussis organisms, used for immunization against pertussis (WHOOPING COUGH). It is generally used in a mixture with diphtheria and tetanus toxoids (DTP). There is an acellular pertussis vaccine prepared from the purified antigenic components of Bordetella pertussis, which causes fewer adverse reactions than whole-cell vaccine and, like the whole-cell vaccine, is generally used in a mixture with diphtheria and tetanus toxoids. (From Dorland, 28th ed)BCG Vaccine: An active immunizing agent and a viable avirulent attenuated strain of Mycobacterium tuberculosis, var. bovis, which confers immunity to mycobacterial infections. It is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.Poliovirus Vaccine, Inactivated: A suspension of formalin-inactivated poliovirus grown in monkey kidney cell tissue culture and used to prevent POLIOMYELITIS.Haemophilus Vaccines: Vaccines or candidate vaccines containing antigenic polysaccharides from Haemophilus influenzae and designed to prevent infection. The vaccine can contain the polysaccharides alone or more frequently polysaccharides conjugated to carrier molecules. It is also seen as a combined vaccine with diphtheria-tetanus-pertussis vaccine.Rabies Vaccines: Vaccines or candidate vaccines used to prevent and treat RABIES. The inactivated virus vaccine is used for preexposure immunization to persons at high risk of exposure, and in conjunction with rabies immunoglobulin, for postexposure prophylaxis.Rotavirus Vaccines: Vaccines or candidate vaccines used to prevent infection with ROTAVIRUS.Cholera Vaccines: Vaccines or candidate vaccines used to prevent infection with VIBRIO CHOLERAE. The original cholera vaccine consisted of killed bacteria, but other kinds of vaccines now exist.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Typhoid-Paratyphoid Vaccines: Vaccines used to prevent TYPHOID FEVER and/or PARATYPHOID FEVER which are caused by various species of SALMONELLA. Attenuated, subunit, and inactivated forms of the vaccines exist.Smallpox Vaccine: A live VACCINIA VIRUS vaccine of calf lymph or chick embryo origin, used for immunization against smallpox. It is now recommended only for laboratory workers exposed to smallpox virus. Certain countries continue to vaccinate those in the military service. Complications that result from smallpox vaccination include vaccinia, secondary bacterial infections, and encephalomyelitis. (Dorland, 28th ed)Tuberculosis Vaccines: Vaccines or candidate vaccines used to prevent or treat TUBERCULOSIS.Chickenpox Vaccine: A live, attenuated varicella virus vaccine used for immunization against chickenpox. It is recommended for children between the ages of 12 months and 13 years.Diphtheria-Tetanus-Pertussis Vaccine: A vaccine consisting of DIPHTHERIA TOXOID; TETANUS TOXOID; and whole-cell PERTUSSIS VACCINE. The vaccine protects against diphtheria, tetanus, and whooping cough.Mumps Vaccine: Vaccines used to prevent infection by MUMPS VIRUS. Best known is the live attenuated virus vaccine of chick embryo origin, used for routine immunization of children and for immunization of adolescents and adults who have not had mumps or been immunized with live mumps vaccine. Children are usually immunized with measles-mumps-rubella combination vaccine.Immunization, Secondary: Any immunization following a primary immunization and involving exposure to the same or a closely related antigen.Hepatitis A Vaccines: Vaccines or candidate vaccines used to prevent infection with hepatitis A virus (HEPATOVIRUS).Immunization Schedule: Schedule giving optimum times usually for primary and/or secondary immunization.Adjuvants, Immunologic: Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (Freund's adjuvant, BCG, Corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity.Measles-Mumps-Rubella Vaccine: A combined vaccine used to prevent MEASLES; MUMPS; and RUBELLA.Dengue Vaccines: Vaccines or candidate vaccines used to prevent infection with DENGUE VIRUS. These include live-attenuated, subunit, DNA, and inactivated vaccines.Streptococcal Vaccines: Vaccines or candidate vaccines used to prevent STREPTOCOCCAL INFECTIONS.Anthrax Vaccines: Vaccines or candidate vaccines used to prevent ANTHRAX.Immunization: Deliberate stimulation of the host's immune response. ACTIVE IMMUNIZATION involves administration of ANTIGENS or IMMUNOLOGIC ADJUVANTS. PASSIVE IMMUNIZATION involves administration of IMMUNE SERA or LYMPHOCYTES or their extracts (e.g., transfer factor, immune RNA) or transplantation of immunocompetent cell producing tissue (thymus or bone marrow).Vaccines, Virosome: Vaccines using VIROSOMES as the antigen delivery system that stimulates the desired immune response.Mice, Inbred BALB CPoliovirus Vaccine, Oral: A live vaccine containing attenuated poliovirus, types I, II, and III, grown in monkey kidney cell tissue culture, used for routine immunization of children against polio. This vaccine induces long-lasting intestinal and humoral immunity. Killed vaccine induces only humoral immunity. Oral poliovirus vaccine should not be administered to immunocompromised individuals or their household contacts. (Dorland, 28th ed)Antibodies, Bacterial: Immunoglobulins produced in a response to BACTERIAL ANTIGENS.Yellow Fever Vaccine: Vaccine used to prevent YELLOW FEVER. It consists of a live attenuated 17D strain of the YELLOW FEVER VIRUS.Plague Vaccine: A suspension of killed Yersinia pestis used for immunizing people in enzootic plague areas.Salmonella Vaccines: Vaccines or candidate vaccines used to prevent infection with SALMONELLA. This includes vaccines used to prevent TYPHOID FEVER or PARATYPHOID FEVER; (TYPHOID-PARATYPHOID VACCINES), and vaccines used to prevent nontyphoid salmonellosis.Viral Hepatitis Vaccines: Any vaccine raised against any virus or viral derivative that causes hepatitis.Fungal Vaccines: Suspensions of attenuated or killed fungi administered for the prevention or treatment of infectious fungal disease.SAIDS Vaccines: Vaccines or candidate vaccines designed to prevent SAIDS; (SIMIAN ACQUIRED IMMUNODEFICIENCY SYNDROME); and containing inactivated SIMIAN IMMUNODEFICIENCY VIRUS or type D retroviruses or some of their component antigens.Rubella Vaccine: A live attenuated virus vaccine of duck embryo or human diploid cell tissue culture origin, used for routine immunization of children and for immunization of nonpregnant adolescent and adult females of childbearing age who are unimmunized and do not have serum antibodies to rubella. Children are usually immunized with measles-mumps-rubella combination vaccine. (Dorland, 28th ed)Vaccines, Acellular: Vaccines that are produced by using only the antigenic part of the disease causing organism. They often require a "booster" every few years to maintain their effectiveness.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Ebola Vaccines: Vaccines or candidate vaccines used to prevent EBOLA HEMORRHAGIC FEVER.Vaccines, Virus-Like Particle: Vaccines using supra-molecular structures composed of multiple copies of recombinantly expressed viral structural proteins. They are often antigentically indistinguishable from the virus from which they were derived.Antibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.Administration, Intranasal: Delivery of medications through the nasal mucosa.Staphylococcal VaccinesCytomegalovirus Vaccines: Vaccines or candidate vaccines used to prevent infection with CYTOMEGALOVIRUS.Injections, Intramuscular: Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.Diphtheria-Tetanus-acellular Pertussis Vaccines: Combined vaccines consisting of DIPHTHERIA TOXOID; TETANUS TOXOID; and an acellular form of PERTUSSIS VACCINE. At least five different purified antigens of B. pertussis have been used in various combinations in these vaccines.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Immunization Programs: Organized services to administer immunization procedures in the prevention of various diseases. The programs are made available over a wide range of sites: schools, hospitals, public health agencies, voluntary health agencies, etc. They are administered to an equally wide range of population groups or on various administrative levels: community, municipal, state, national, international.Escherichia coli Vaccines: Vaccines or candidate vaccines used to prevent or treat both enterotoxigenic and enteropathogenic Escherichia coli infections.Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).West Nile Virus Vaccines: Vaccines or candidate vaccines used to prevent infection with WEST NILE VIRUS.Hemagglutination Inhibition Tests: Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.Poliovirus Vaccines: Vaccines used to prevent POLIOMYELITIS. They include inactivated (POLIOVIRUS VACCINE, INACTIVATED) and oral vaccines (POLIOVIRUS VACCINE, ORAL).Shigella Vaccines: Vaccines or candidate vaccines used to prevent bacillary dysentery (DYSENTERY, BACILLARY) caused by species of SHIGELLA.Mice, Inbred C57BLAntibody Formation: The production of ANTIBODIES by proliferating and differentiated B-LYMPHOCYTES under stimulation by ANTIGENS.Diphtheria-Tetanus Vaccine: A combined vaccine used to prevent infection with diphtheria and tetanus toxoid. This is used in place of DTP vaccine (DIPHTHERIA-TETANUS-PERTUSSIS VACCINE) when PERTUSSIS VACCINE is contraindicated.Brucella Vaccine: A bacterial vaccine for the prevention of brucellosis in man and animal. Brucella abortus vaccine is used for the immunization of cattle, sheep, and goats.Immunity, Humoral: Antibody-mediated immune response. Humoral immunity is brought about by ANTIBODY FORMATION, resulting from TH2 CELLS activating B-LYMPHOCYTES, followed by COMPLEMENT ACTIVATION.Herpes Zoster Vaccine: An attenuated vaccine used to prevent and/or treat HERPES ZOSTER, a disease caused by HUMAN HERPESVIRUS 3.Polysorbates: Sorbitan mono-9-octadecanoate poly(oxy-1,2-ethanediyl) derivatives; complex mixtures of polyoxyethylene ethers used as emulsifiers or dispersing agents in pharmaceuticals.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Herpesvirus Vaccines: Vaccines or candidate vaccines used to prevent infection by any virus from the family HERPESVIRIDAE.Injections, Intradermal: The forcing into the skin of liquid medication, nutrient, or other fluid through a hollow needle, piercing the top skin layer.Antigens, Bacterial: Substances elaborated by bacteria that have antigenic activity.Influenza A Virus, H1N1 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.Leishmaniasis Vaccines: Vaccines or candidate vaccines used to prevent infection with LEISHMANIA.Respiratory Syncytial Virus Vaccines: Vaccines or candidate vaccines used to prevent infection with RESPIRATORY SYNCYTIAL VIRUSES.Genetic Vectors: DNA molecules capable of autonomous replication within a host cell and into which other DNA sequences can be inserted and thus amplified. Many are derived from PLASMIDS; BACTERIOPHAGES; or VIRUSES. They are used for transporting foreign genes into recipient cells. Genetic vectors possess a functional replicator site and contain GENETIC MARKERS to facilitate their selective recognition.Tetanus ToxoidHerpes Simplex Virus Vaccines: Vaccines or candidate vaccines used to prevent infection with viruses from the genus SIMPLEXVIRUS. This includes vaccines for HSV-1 and HSV-2.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Alum Compounds: Aluminum metal sulfate compounds used medically as astringents and for many industrial purposes. They are used in veterinary medicine for the treatment of ulcerative stomatitis, leukorrhea, conjunctivitis, pharyngitis, metritis, and minor wounds.Aluminum Hydroxide: A compound with many biomedical applications: as a gastric antacid, an antiperspirant, in dentifrices, as an emulsifier, as an adjuvant in bacterins and vaccines, in water purification, etc.Japanese Encephalitis Vaccines: Vaccines or candidate vaccines used to prevent infection with Japanese B encephalitis virus (ENCEPHALITIS VIRUS, JAPANESE).Cross Protection: Protection conferred on a host by inoculation with one strain or component of a microorganism that prevents infection when later challenged with a similar strain. Most commonly the microorganism is a virus.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Diphtheria Toxoid: The formaldehyde-inactivated toxin of Corynebacterium diphtheriae. It is generally used in mixtures with TETANUS TOXOID and PERTUSSIS VACCINE; (DTP); or with tetanus toxoid alone (DT for pediatric use and Td, which contains 5- to 10-fold less diphtheria toxoid, for other use). Diphtheria toxoid is used for the prevention of diphtheria; DIPHTHERIA ANTITOXIN is for treatment.SqualeneVirulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.CD8-Positive T-Lymphocytes: A critical subpopulation of regulatory T-lymphocytes involved in MHC Class I-restricted interactions. They include both cytotoxic T-lymphocytes (T-LYMPHOCYTES, CYTOTOXIC) and CD8+ suppressor T-lymphocytes.Mass Vaccination: Administration of a vaccine to large populations in order to elicit IMMUNITY.Immunity, Cellular: Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Vaccines, Contraceptive: Vaccines or candidate vaccines used to prevent conception.Interferon-gamma: The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.Vaccines, Edible: Vaccines or candidate vaccines derived from edible plants. Transgenic plants (PLANTS, TRANSGENIC) are used as recombinant protein production systems and the edible plant tissue functions as an oral vaccine.Macaca mulatta: A species of the genus MACACA inhabiting India, China, and other parts of Asia. The species is used extensively in biomedical research and adapts very well to living with humans.Immunity, Mucosal: Nonsusceptibility to the pathogenic effects of foreign microorganisms or antigenic substances as a result of antibody secretions of the mucous membranes. Mucosal epithelia in the gastrointestinal, respiratory, and reproductive tracts produce a form of IgA (IMMUNOGLOBULIN A, SECRETORY) that serves to protect these ports of entry into the body.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Measles: A highly contagious infectious disease caused by MORBILLIVIRUS, common among children but also seen in the nonimmune of any age, in which the virus enters the respiratory tract via droplet nuclei and multiplies in the epithelial cells, spreading throughout the MONONUCLEAR PHAGOCYTE SYSTEM.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Whooping Cough: A respiratory infection caused by BORDETELLA PERTUSSIS and characterized by paroxysmal coughing ending in a prolonged crowing intake of breath.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Immunotherapy, Active: Active immunization where vaccine is administered for therapeutic or preventive purposes. This can include administration of immunopotentiating agents such as BCG vaccine and Corynebacterium parvum as well as biological response modifiers such as interferons, interleukins, and colony-stimulating factors in order to directly stimulate the immune system.Cross Reactions: Serological reactions in which an antiserum against one antigen reacts with a non-identical but closely related antigen.Parainfluenza Vaccines: Vaccines or candidate vaccines used to prevent infection with parainfluenza viruses in humans and animals.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Smallpox: An acute, highly contagious, often fatal infectious disease caused by an orthopoxvirus characterized by a biphasic febrile course and distinctive progressive skin eruptions. Vaccination has succeeded in eradicating smallpox worldwide. (Dorland, 28th ed)Influenza A Virus, H3N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 2. The H3N2 subtype was responsible for the Hong Kong flu pandemic of 1968.Vaccine Potency: The relationship between an elicited ADAPTIVE IMMUNE RESPONSE and the dose of the vaccine administered.Influenza B virus: Species of the genus INFLUENZAVIRUS B that cause HUMAN INFLUENZA and other diseases primarily in humans. Antigenic variation is less extensive than in type A viruses (INFLUENZA A VIRUS) and consequently there is no basis for distinct subtypes or variants. Epidemics are less likely than with INFLUENZA A VIRUS and there have been no pandemics. Previously only found in humans, Influenza B virus has been isolated from seals which may constitute the animal reservoir from which humans are exposed.Influenza A Virus, H5N1 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 5 and neuraminidase 1. The H5N1 subtype, frequently referred to as the bird flu virus, is endemic in wild birds and very contagious among both domestic (POULTRY) and wild birds. It does not usually infect humans, but some cases have been reported.Rotavirus Infections: Infection with any of the rotaviruses. Specific infections include human infantile diarrhea, neonatal calf diarrhea, and epidemic diarrhea of infant mice.T-Lymphocytes: Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.CD4-Positive T-Lymphocytes: A critical subpopulation of T-lymphocytes involved in the induction of most immunological functions. The HIV virus has selective tropism for the T4 cell which expresses the CD4 phenotypic marker, a receptor for HIV. In fact, the key element in the profound immunosuppression seen in HIV infection is the depletion of this subset of T-lymphocytes.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Rickettsial Vaccines: Vaccines for the prevention of diseases caused by various species of Rickettsia.Orthomyxoviridae Infections: Virus diseases caused by the ORTHOMYXOVIRIDAE.Pseudorabies Vaccines: Vaccines or candidate vaccines used to prevent PSEUDORABIES (Aujeszky's disease), a herpesvirus of swine and other animals.Poliomyelitis: An acute infectious disease of humans, particularly children, caused by any of three serotypes of human poliovirus (POLIOVIRUS). Usually the infection is limited to the gastrointestinal tract and nasopharynx, and is often asymptomatic. The central nervous system, primarily the spinal cord, may be affected, leading to rapidly progressive paralysis, coarse FASCICULATION and hyporeflexia. Motor neurons are primarily affected. Encephalitis may also occur. The virus replicates in the nervous system, and may cause significant neuronal loss, most notably in the spinal cord. A rare related condition, nonpoliovirus poliomyelitis, may result from infections with nonpoliovirus enteroviruses. (From Adams et al., Principles of Neurology, 6th ed, pp764-5)Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Hemagglutinin Glycoproteins, Influenza Virus: Membrane glycoproteins from influenza viruses which are involved in hemagglutination, virus attachment, and envelope fusion. Fourteen distinct subtypes of HA glycoproteins and nine of NA glycoproteins have been identified from INFLUENZA A VIRUS; no subtypes have been identified for Influenza B or Influenza C viruses.Influenza A virus: The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.T-Lymphocytes, Cytotoxic: Immunized T-lymphocytes which can directly destroy appropriate target cells. These cytotoxic lymphocytes may be generated in vitro in mixed lymphocyte cultures (MLC), in vivo during a graft-versus-host (GVH) reaction, or after immunization with an allograft, tumor cell or virally transformed or chemically modified target cell. The lytic phenomenon is sometimes referred to as cell-mediated lympholysis (CML). These CD8-positive cells are distinct from NATURAL KILLER CELLS and NATURAL KILLER T-CELLS. There are two effector phenotypes: TC1 and TC2.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Rabies: Acute VIRAL CNS INFECTION affecting mammals, including humans. It is caused by RABIES VIRUS and usually spread by contamination with virus-laden saliva of bites inflicted by rabid animals. Important animal vectors include the dog, cat, bat, fox, raccoon, skunk, and wolf.Dose-Response Relationship, Immunologic: A specific immune response elicited by a specific dose of an immunologically active substance or cell in an organism, tissue, or cell.Yellow fever virus: The type species of the FLAVIVIRUS genus. Principal vector transmission to humans is by AEDES spp. mosquitoes.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.Drug Storage: The process of keeping pharmaceutical products in an appropriate location.Epitopes, T-Lymphocyte: Antigenic determinants recognized and bound by the T-cell receptor. Epitopes recognized by the T-cell receptor are often located in the inner, unexposed side of the antigen, and become accessible to the T-cell receptors after proteolytic processing of the antigen.Papillomavirus Infections: Neoplasms of the skin and mucous membranes caused by papillomaviruses. They are usually benign but some have a high risk for malignant progression.Protozoan Proteins: Proteins found in any species of protozoan.Cytokines: Non-antibody proteins secreted by inflammatory leukocytes and some non-leukocytic cells, that act as intercellular mediators. They differ from classical hormones in that they are produced by a number of tissue or cell types rather than by specialized glands. They generally act locally in a paracrine or autocrine rather than endocrine manner.Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Bacterial Proteins: Proteins found in any species of bacterium.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Reassortant Viruses: Viruses containing two or more pieces of nucleic acid (segmented genome) from different parents. Such viruses are produced in cells coinfected with different strains of a given virus.Dendritic Cells: Specialized cells of the hematopoietic system that have branch-like extensions. They are found throughout the lymphatic system, and in non-lymphoid tissues such as SKIN and the epithelia of the intestinal, respiratory, and reproductive tracts. They trap and process ANTIGENS, and present them to T-CELLS, thereby stimulating CELL-MEDIATED IMMUNITY. They are different from the non-hematopoietic FOLLICULAR DENDRITIC CELLS, which have a similar morphology and immune system function, but with respect to humoral immunity (ANTIBODY PRODUCTION).Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Immunity: Nonsusceptibility to the invasive or pathogenic effects of foreign microorganisms or to the toxic effect of antigenic substances.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.Meningococcal Infections: Infections with bacteria of the species NEISSERIA MENINGITIDIS.Vaccines, Marker: Vaccines used in conjunction with diagnostic tests to differentiate vaccinated animals from carrier animals. Marker vaccines can be either a subunit or a gene-deleted vaccine.Haemophilus influenzae type b: A type of H. influenzae isolated most frequently from biotype I. Prior to vaccine availability, it was a leading cause of childhood meningitis.Mumps: An acute infectious disease caused by RUBULAVIRUS, spread by direct contact, airborne droplet nuclei, fomites contaminated by infectious saliva, and perhaps urine, and usually seen in children under the age of 15, although adults may also be affected. (From Dorland, 28th ed)Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Immunotherapy: Manipulation of the host's immune system in treatment of disease. It includes both active and passive immunization as well as immunosuppressive therapy to prevent graft rejection.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Neisseria meningitidis, Serogroup B: Strains of Neisseria meningitidis which are the most common ones causing infections or disease in infants. Serogroup B strains are isolated most frequently in sporadic cases, and are less common in outbreaks and epidemics.Immunity, Herd: The non-susceptibility to infection of a large group of individuals in a population. A variety of factors can be responsible for herd immunity and this gives rise to the different definitions used in the literature. Most commonly, herd immunity refers to the case when, if most of the population is immune, infection of a single individual will not cause an epidemic. Also, in such immunized populations, susceptible individuals are not likely to become infected. Herd immunity can also refer to the case when unprotected individuals fail to contract a disease because the infecting organism has been banished from the population.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Pandemics: Epidemics of infectious disease that have spread to many countries, often more than one continent, and usually affecting a large number of people.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Lyme Disease Vaccines: Vaccines or candidate vaccines used to prevent LYME DISEASE.United StatesRabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Tetanus: A disease caused by tetanospasmin, a powerful protein toxin produced by CLOSTRIDIUM TETANI. Tetanus usually occurs after an acute injury, such as a puncture wound or laceration. Generalized tetanus, the most common form, is characterized by tetanic muscular contractions and hyperreflexia. Localized tetanus presents itself as a mild condition with manifestations restricted to muscles near the wound. It may progress to the generalized form.Rabies virus: The type species of LYSSAVIRUS causing rabies in humans and other animals. Transmission is mostly by animal bites through saliva. The virus is neurotropic multiplying in neurons and myotubes of vertebrates.Pseudomonas Vaccines: Vaccines or candidate vaccines used to prevent or treat PSEUDOMONAS INFECTIONS.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Injections, Subcutaneous: Forceful administration under the skin of liquid medication, nutrient, or other fluid through a hollow needle piercing the skin.HIV Antibodies: Antibodies reactive with HIV ANTIGENS.Immunologic Memory: The altered state of immunologic responsiveness resulting from initial contact with antigen, which enables the individual to produce antibodies more rapidly and in greater quantity in response to secondary antigenic stimulus.Ferrets: Semidomesticated variety of European polecat much used for hunting RODENTS and/or RABBITS and as a laboratory animal. It is in the subfamily Mustelinae, family MUSTELIDAE.Lymphocyte Activation: Morphologic alteration of small B LYMPHOCYTES or T LYMPHOCYTES in culture into large blast-like cells able to synthesize DNA and RNA and to divide mitotically. It is induced by INTERLEUKINS; MITOGENS such as PHYTOHEMAGGLUTININS, and by specific ANTIGENS. It may also occur in vivo as in GRAFT REJECTION.Simian immunodeficiency virus: Species of the genus LENTIVIRUS, subgenus primate immunodeficiency viruses (IMMUNODEFICIENCY VIRUSES, PRIMATE), that induces acquired immunodeficiency syndrome in monkeys and apes (SAIDS). The genetic organization of SIV is virtually identical to HIV.Enzyme-Linked Immunospot Assay: A method of detection of the number of cells in a sample secreting a specific molecule. With this method, a population of cells are plated over top of the immunosorbent substrate that captures the secreted molecules.Bordetella pertussis: A species of gram-negative, aerobic bacteria that is the causative agent of WHOOPING COUGH. Its cells are minute coccobacilli that are surrounded by a slime sheath.Meningitis, Meningococcal: A fulminant infection of the meninges and subarachnoid fluid by the bacterium NEISSERIA MENINGITIDIS, producing diffuse inflammation and peri-meningeal venous thromboses. Clinical manifestations include FEVER, nuchal rigidity, SEIZURES, severe HEADACHE, petechial rash, stupor, focal neurologic deficits, HYDROCEPHALUS, and COMA. The organism is usually transmitted via nasopharyngeal secretions and is a leading cause of meningitis in children and young adults. Organisms from Neisseria meningitidis serogroups A, B, C, Y, and W-135 have been reported to cause meningitis. (From Adams et al., Principles of Neurology, 6th ed, pp689-701; Curr Opin Pediatr 1998 Feb;10(1):13-8)Plasmids: Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.Rotavirus: A genus of REOVIRIDAE, causing acute gastroenteritis in BIRDS and MAMMALS, including humans. Transmission is horizontal and by environmental contamination. Seven species (Rotaviruses A thru G) are recognized.Bacterial Outer Membrane Proteins: Proteins isolated from the outer membrane of Gram-negative bacteria.Plague: An acute infectious disease caused by YERSINIA PESTIS that affects humans, wild rodents, and their ectoparasites. This condition persists due to its firm entrenchment in sylvatic rodent-flea ecosystems throughout the world. Bubonic plague is the most common form.Hepatitis B Antibodies: Antibodies to the HEPATITIS B ANTIGENS, including antibodies to the surface (Australia) and core of the Dane particle and those to the "e" antigens.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Epitopes, B-Lymphocyte: Antigenic determinants recognized and bound by the B-cell receptor. Epitopes recognized by the B-cell receptor are located on the surface of the antigen.Salmonella typhi: A serotype of SALMONELLA ENTERICA which is the etiologic agent of TYPHOID FEVER.Diphtheria: A localized infection of mucous membranes or skin caused by toxigenic strains of CORYNEBACTERIUM DIPHTHERIAE. It is characterized by the presence of a pseudomembrane at the site of infection. DIPHTHERIA TOXIN, produced by C. diphtheriae, can cause myocarditis, polyneuritis, and other systemic toxic effects.Francisella tularensis: The etiologic agent of TULAREMIA in man and other warm-blooded animals.Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Immunity, Active: Resistance to a disease agent resulting from the production of specific antibodies by the host, either after exposure to the disease or after vaccination.Biolistics: Techniques where DNA is delivered directly into organelles at high speed using projectiles coated with nucleic acid, shot from a helium-powered gun (gene gun). One of these techniques involves immunization by DNA VACCINES, which delivers DNA-coated gold beads to the epidermis.Adenoviridae: A family of non-enveloped viruses infecting mammals (MASTADENOVIRUS) and birds (AVIADENOVIRUS) or both (ATADENOVIRUS). Infections may be asymptomatic or result in a variety of diseases.Spleen: An encapsulated lymphatic organ through which venous blood filters.Chickenpox: A highly contagious infectious disease caused by the varicella-zoster virus (HERPESVIRUS 3, HUMAN). It usually affects children, is spread by direct contact or respiratory route via droplet nuclei, and is characterized by the appearance on the skin and mucous membranes of successive crops of typical pruritic vesicular lesions that are easily broken and become scabbed. Chickenpox is relatively benign in children, but may be complicated by pneumonia and encephalitis in adults. (From Dorland, 27th ed)Antigens, Neoplasm: Proteins, glycoprotein, or lipoprotein moieties on surfaces of tumor cells that are usually identified by monoclonal antibodies. Many of these are of either embryonic or viral origin.Poliovirus: A species of ENTEROVIRUS which is the causal agent of POLIOMYELITIS in humans. Three serotypes (strains) exist. Transmission is by the fecal-oral route, pharyngeal secretions, or mechanical vector (flies). Vaccines with both inactivated and live attenuated virus have proven effective in immunizing against the infection.