Strains vaccine

Lougovskoi, A.A., Okoyeh, N.J., and Chauhan, V.S. (1999) Mice immunised with synthetic peptide from N-terminal conserved region of merozoite surface antigen-2 of human malaria parasite Plasmodium falciparum can control infection induced by Plasmodium yoeliiyoelii 265BY strain. Vaccine 18(9-10), 920-930. 

Maassen, C.B., van Holten-Neelen, C., Balk, F., Heijne den Bak-Glashouwer, M., Leer, R.J., and Laman, J.D. 2000. Strain-dependent induction of cytokine profiles in the gut by orally-administered Lactobacillus strains. Vaccine 18 2613-2623. 

Composition and Methods of Manufacture. Vaccine is produced from the Oka attenuated strain. Vaccine is produced in human diploid cells such as MRC-5. After growth in the cell substrate, the cells themselves are harvested into the growth medium and sonicated to release the cell-associated vims. Sucrose and buffering salts are generally in the medium to help stabilize the vims. The vaccine is presented in a freeze-dried vial to be reconstituted with sterile distilled water before injection (27). 

Kurane I, Takasaki T. Immunogenicity and protective efficacy of the current inactivated Japanese encephalitis vaccine against different Japanese encephalitis virus strains. Vaccine 2000 18(Suppl 2) 33-5. 

A live attenuated Varicella vaccine was developed in 1973 by Takahashi using the Oka strain, which was isolated from a boy with chickenpox and named after the boy. Several producers use this live vaccine strain, for example Biken Institute, Merck, Sharp Dohme, and SmithKline Beecham. Whereas the first Oka strain vaccines needed to be stored at —20°C, subsequent reformulation of the vaccine provided a shelf-life of up to 2 years at -t-2 C, with... 

J. Tree, C. Riehardson, A. Fooks, J. Clegg, D. Looby, 2001. Comparison of large-scale mammalian cell culture systems with egg culture for the production of influenza virus A vaccine strains. Vaccine 19, 3444-3450. 

In cases where a relevant species has not been identified, a multifaceted approach may be taken. This was the case for S. typhi, a human-restricted strain vaccine, which used a combination of in vitro and in vivo studies and a weight of evidence approach. Also, by changing the formulation to include hog mucin and the route of administration from subcutaneous to intraperitoneal, the mouse, which was previously not sensitive, became sensitive to the pathogen, which enabled levels of attenuation to be assessed. The vaccine entered into a phase I clinical trial with no reported safety issues.27... 

CHENG, s., ZHANG, w.-w., ZHANG, M. and SUN, L. (2010c) Evaluation of the vaccine potential of a cytotoxic protease and a protective immunogen from a pathogenic Vibrio harveyi strain. Vaccine 28,1041-1047. 

SUN, Y., LIU, C.-S. and sun, l. (2010a) Identification of an Edwardsiella tarda snrface antigen and analysis of its immnnoprotective potential as a pnrified recombinant subunit vaccine and a snrface-anchored snbnnit vaccine expressed by a fish commensal strain. Vaccine 28, 6603-6608. 

Preventive medicine through vaccination continues to be the most cost-effective pubHc health practice, even with the drastic advance in modern medicine. Mass vaccination programs have eradicated smallpox from the earth. The World Health Organization (WHO) has a major campaign underway to eradicate poHo by the year 2000. The development of vaccines has saved millions of Hves and prevented many more from suffering. However, there are stiU many diseases without effective vaccines, such as malaria. With the recent emergence of antibiotic-resistance strains and exotic vimses, an effective vaccine development program becomes a top priority of pubHc health poHcy. 

Live vaccines are normally weakened strains that do not cause diseases in the host, but stiU can stimulate the immune response. A typical example is the poho vaccine. The weakening of microorganisms or attenuation of the vims or bacteria can be accompHshed by passage through different substrates and/or at different temperatures. Modem genetic engineering techniques can also be used to attenuate a vims or bacterium. 

Composition and Methods of Manufacture. Two types of influen2a vimses, A and B, are responsible for causing periodic outbreaks of febrile respiratory disease. The manufacture of an effective vaccine is compHcated by antigenic variation or drift, which can occur from year to year within the two vims types, making the previous year s vaccine less effective. Each year, antigenic characteri2ation is important for selecting the vims strains to be included in the vaccine. 

Active immunization against the specific influenza virus strains contained in the formulation Same as for BCG vaccine One or two doses of 0.25-0.5 mL IM... 

The starting point for the produchon of all microbial vaccines is the isolation of the appropriate microbe. Such isolates have been mostly derived from human infections and in some cases have yielded strains suitable for vaccine production very readily in other cases a great deal of manipulahon and selechon in the laboratory have been needed before a suitable strain has been obtained. 

Once a suitable strain is available, the prachce is to grow, often ftom a single organism, a sizeable culture which is distributed in small amounts in a large number of ampoules and then stored at 70°C or freeze-dried. This is the seed lot. From this seed lot, one or more ampoules are taken and used as the seed to originate a limited number of batches of vaccine which are first examined exhaustively in the laboratory and then, if found to be satisfactory, tested for safety and efficacy in clinical trials. Satisfactory results in the clinical trials validate the seed lot as the seed from which batches of vaccine for routine use can subsequently be produced. 

Viruses replicate only in living cells so the first viral vaccines were necessarily made in animals smallpox vaccine in the dermis of calves and sheep and rabies vaccines in the spinal cords of rabbits and the brains of mice. Such methods are no longer used in advanced vaccine production and the only intact animal hosts that are used are embryonated hens eggs. Almost all of the vims that is needed for viral vaccine production is obtained from cell cultures infected with vims of the appropriate strain. 

The single-component viral vaccines are listed in Table 15.2 with notes similar to those provided with the bacterial vaccines. The only eombined viral vaeeine that is widely used is the measles, mumps and rubella vaccine (MMR Vac). In a sense, however, both the inactivated (Salk) poliovaccine (PoWac (inactivated)) and the live (Sabin) poliovaccine (PolWac (oral)) are combined vaccines in that they are both mixtures of vims of each of the three serotypes of poliovims. Influenza vaeeines, too, are eombined vaccines in that many contain components fiom as many as three vims strains, usually fiom two strains of influenza A and one strain of influenza B. 

Faecal excretion of vaeeine virus will oeeur and may last for up to 6 weeks. Such released virus will spread to elose eontaets and infect/(re)immunize them. Since the introduction of OPV, notifications of paralytic poliomyelitis in the UK have dropped speetacularly. From 1985-95, 19 of the 28 notified cases of paralytic poliomyelitis were associated with vaeeine strains (14 reeipients, 5 contacts). Vaccine-associated poliomyelitis may occur through reversion of the attenuated strains to the virulent wild-... 

A live vaccine strain of measles (Chapter 15) was introduced in the USA in 1962 and to the UK in 1968. A single injection produces high-level immunity in over 95% of recipients. Moreover, since the vaccine induces immunity more rapidly than the natural infection, it may be used to control the impact of measles outbreaks. The measles virus cannot survive outside ofan infected host. Widespread use ofthe vaccine therefore has the potential, as with smallpox, of eliminating the disease worldwide. Mass immunization has reduced the incidence of measles to almost nil, although a 15-fold increase in the incidence was noted in the USA between 1989 and 1991 because of poor compliance. 

Haemophilus influenzae is a bacterial respiratory pathogen that causes a wide spectrum of disease ranging from colonization of the airways to bacterial meningitis. It causes considerable morbidity and mortality, especially in children less than 5 years of age. H. influenzae is either encapsulated or unencapsulated. The encapsulated strains can be further differentiated into six antigenically distinct serotypes, a through f. H. influenzae type b was primarily found in cerebrospinal fluid and blood of children with meningitis, while the unencapsulated strains were found in the upper respiratory tract of adults. Before the introduction of the vaccine, H. influenzae was responsible for 20,000 to 25,000 cases of invasive disease annually and was the most common cause of bacterial meningitis. Since the introduction of the vaccine, invasive disease due to H. influenzae type b has been nearly eliminated. 

Healthy individuals 5 to 49 years of age can receive the live attenuated influenza vaccine instead of the inactivated vaccine. There are limited data on transmission of the vaccine strain following intranasal vaccination however, secondary transmission does not appear to be a concern. 

Since the introduction of the mumps vaccine in 1967 there has been a 99% reduction in reported cases. The mumps vaccine is a live virus preparation of the leryl-Lynn strain. It produces a sub-clinical, non-communicable infection following vaccination. Single doses of mumps vaccine will elicit immunity in 75% to 95% of individuals. Vaccine-induced immunity lasts for more than 30 years. 

The live rubella vaccine available in the United States contains the RA 27/3 strain of the virus. Following a single dose of rubella vaccine after the first birthday, more than 90% of individuals will develop long-term immunity. Rarely has congenital rubella syndrome been reported in infants born to mothers with adequate rubella immunization. 

The 23-valent pneumococcal polysaccharide vaccine contains 23 serotypes that are responsible for causing more than 80% of invasive S. pneumoniae infections in adults. The vaccine includes those serotypes that are associated with drug resistance. Use of the vaccine will not prevent the development of antibiotic-resistant S. pneumoniae, but is likely to prevent infection from drug-resistant strains. The 23-valent pneumococcal polysaccharide vaccine has demonstrated good immunogenicity in adults, but an individual will not develop immunity to all 23 serotypes following vaccination.10... 

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