Vaccine, killed

Leptospira vaccines Killed strain of Leptospira interogans... 

Vaccines—Killed or weakened disease-causing organisms or materials from them that can be used to stimulate the immune system to develop resistance. 

Leptospira vaccines Killed strain of Leptospira interogans Active immunization against leptospirosis icterohaemor-rhagica (Weil s disease)... 

Pertussis vaccines Killed strain(s) of Bordetella pertussis Active immunization against whooping cough... 

Typhoid vaccines Killed Salmonella typhi Active immunization against typhoid fever... 

Typhus vaccines Killed epidemic Rickettsia prowazekii Active immunization against louse-borne t q)hus... 

Retrodrine hydrochloride Rhinopneumonitis vaccine Antirabies vaccine (killed) Ribavirin (virazole)... 

Killed vaccines. Killed vaccines are suspensions of bacteria, viruses or other pathogenic agents, that have been killed by heat or by disinfectants such as phenol, ethanol or formaldehyde. Killed microorganisms obviously cannot replicate and cause an infection and so it is necessary for each dose of a killed vaccine to contain sufficient antigenic material to stimulate a protective immune response. Killed vaccines therefore usually have to be relatively concentrated suspensions. Even so, such preparations are often rather poorly protective, possibly because of partial destruction of protective antigens during the killing process or inadequate expression... 

Vaccines can be roughly categorized into killed vaccines and Hve vaccines. A killed vaccine can be (/) an inactivated, whole microorganism such as pertussis, (2) an inactivated toxin, called toxoid, such as diphtheria toxoid, or (J) one or more components of the microorganism commonly referred to as subunit vaccines. The examples are capsular polysaccharide of Streptococcus pneumoniae and the surface antigen protein for Hepatitis B vims vaccine. 

Poliomyelitis. Two vaccines are Hcensed for the control of poliomyelitis in the United States. The Hve, attenuated oral polio vims (OPV) vaccine can be used for the immunization of normal children. The killed or inactivated vaccine is recommended for immunization of adults at increased... 

In the preparation of classical killed or toxoid vaccines, simple process technology was used. With the advance of new vaccines, far more sophisticated process technologies are needed. The desire to reduce side effects of vaccination requires processes which will yield antigens of extreme purity. The new regulation in cGMP requires consistent production procedures, and global competition also demands that the most efficient process technology be appHed. 

Vaccine A suspension of attenuated or killed bacteria or virus, or portions thereof, injected to produce active immunity. 

An example of the use of an attenuated virus is the administration of the measles vaccine to an individual who has not had measles. The m easles (rubeola) vaccine contains the live, attenuated measles virus. The individual receiving the vaccine develops a mild or modified measles infection, which then produces immunity against the rubeola virus. The measles vaccine protects 95% of the recipients for several years or, for some individuals, for life. An example of a killed virus used for immunization is the cholera vaccine. This vaccine protects those who receive the vacdne for about 3 to 6 months. 

Killing. The proeess by which the live bacteria in the culture are killed and thus rendered harmless. Heat and disinfectants are employed. Heat and/or formalin are required to kill the cells of Bordetella pertussis used to make whooping-cough vaccines, and phenol is used to kill the Vibrio cholerae in cholera vaccine and the Salmonella typhi in typhoid vaeeine. 

Viral vaccines present problems of safety testing far more complex than those experienced with bacterial vaccines. With killed viral vaccines the potential hazards are those due to incomplete virus inactivation and the consequent presence of residual live virus in the preparation. The tests used to detect such live virus consist of the inoculation of susceptible tissue cultures and of susceptible animals. The cultures are examined for cytopathic effects and the animals for symptoms of disease and histological evidence of infection at autopsy. This test is of particular importance in inactivated poliomyelitis vaccine, the vaccine being injected intraspinally into monkeys. At autopsy, sections of brain and spinal cord are examined microscopically for the histological lesions indicative of proliferating poliovirus. 

Vaccines may be considered as representing live microorganisms, killed miciooiganisms or purified bacterial and viral components (component vaccines). These vaccine classes have been deseribed in detail in Chapter 15. Some additional points about their use are diseussed below. 

Since these vaecines are imable to evoke a natural infection profile with respeet to the release of antigen they must be administered on a number of occasions. Immunity is not complete until the course of immunization is complete and, with the exeeption of toxin-dominated diseases (diphtheria, tetanus) where the immimogen is a toxoid, will never match the performance of live vaccine delivery. Specificity of the immrme resporrse generated in the patient is initially low. This is particularly the case when the vaeeine is composed of a relatively crude cocktail of killed cells where the immime response is direeted only partly towards antigenic components of the cells that are assoeiated with the infeetion process. This increases the possibility of adverse reaetions in the patient. 

Polio is the only disease, at present, for which both hve and killed vaccines compete. Since the introduction of the killed vims (Salk) in 1956 and the live attenuated virus (Sabin) in 1962 there has been a remaikable decline in the incidence of poliomyelitis (Fig. 16.1). The inactivated polio vaccine (TPV) contains formalin-killed poliovirus of all three serotypes. On injection, the vaccine stimulates the production of antibodies of the IgM and IgG class which neutrahze the vims in the second stage of infection. A course of three injections at monthly intervals produces long-lasting immunity to all three poliovirus types. 

The first pertussis whole cell vaccine was a mixture of killed organisms that was associated with frequent local and systemic reactions. In the late 1980s, an acellular pertussis vaccine was introduced that contains purified pertussis components that are immunogenic but associated with fewer adverse reactions. Acellular pertussis vaccine is available in combination with tetanus and diphtheria toxoids. Pertussis is not available as a separate vaccine component. In the spring of 2005, the Food and Drug Administration (FDA) approved tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccines for use in adolescents and adults. 

Finch, J.M., Hill, A.W., Field, T.R. and Leigh, J.A. (1994), Local vaccination with killed Streptococcus uberis protects the bovine mammary gland against experimental intramammary challenge with the homologous strain . Infection and Immunity, 62, 3599-3603. 

Vaccination to induce an adaptive immune response is expected for a broad range of infectious diseases and cancers. Traditional vaccines are mainly composed of live attenuated viruses, whole inactivated pathogens, or inactivated bacterial toxins. In general, these approaches have been successful for developing vaccines that can induce an immune response based on antigen-specific antibody and cytotoxic T lymphocyte (CTL) responses, which kill host cells infected with intracellular organisms (Fig. 1) [1,2], One of the most important current issues in vaccinology is the need for new adjuvants (immunostimulants) and delivery systems. Many of the vaccines currently in development are based on purified subunits, recombinant... 

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