Biomaterial Database

BCG--different strains, different vaccines? 2002

Marcel A Behr

McGill University Health Centre, Montreal, Canada. marcel.behr@mcgill.ca

After nearly a century of use, BCG vaccines continue to generate controversy and confusion. Their ability to prevent tuberculosis in studies has been inconsistent. When they have been protective, no clear mechanism of action has been established. Furthermore, the existence of different BCG strains has been described since the 1940s. These strains vary according to several laboratory properties, which may or may not translate into a discernible effect on vaccination. With recent genomic comparisons, it is now clear that different BCG vaccine strains have evolved and differ from each other and from the original BCG first used in 1921. Some of these genetic alterations explain certain variations in laboratory properties of BCG. However, these mutations in BCG strains have yet to be shown to affect BCG-associated protection and/or adverse effects. Continuing research is attempting to assess the effect of these genetic alterations on properties of BCG strains, with the goals of suggesting the ideal BCG for vaccination and providing avenues for improvement on existing BCG vaccines.

UI	MeSH Term	Description	Entries
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D009169	Mycobacterium tuberculosis	A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.	Mycobacterium tuberculosis H37Rv
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001500	BCG Vaccine	An active immunizing agent and a viable avirulent attenuated strain of MYCOBACTERIUM 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.	Bacillus Calmette Guerin Vaccine,Calmette Guerin Bacillus Vaccine,Calmette's Vaccine,Calmette Vaccine,Calmettes Vaccine,Vaccine, BCG,Vaccine, Calmette's
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species
D014376	Tuberculosis	Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM TUBERCULOSIS.	Koch's Disease,Kochs Disease,Mycobacterium tuberculosis Infection,Infection, Mycobacterium tuberculosis,Infections, Mycobacterium tuberculosis,Koch Disease,Mycobacterium tuberculosis Infections,Tuberculoses
D017353	Gene Deletion	A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.	Deletion, Gene,Deletions, Gene,Gene Deletions
D049673	History, 20th Century	Time period from 1901 through 2000 of the common era.	20th Century History,20th Cent. History (Medicine),20th Cent. History of Medicine,20th Cent. Medicine,Historical Events, 20th Century,History of Medicine, 20th Cent.,History, Twentieth Century,Medical History, 20th Cent.,Medicine, 20th Cent.,20th Cent. Histories (Medicine),20th Century Histories,Cent. Histories, 20th (Medicine),Cent. History, 20th (Medicine),Century Histories, 20th,Century Histories, Twentieth,Century History, 20th,Century History, Twentieth,Histories, 20th Cent. (Medicine),Histories, 20th Century,Histories, Twentieth Century,History, 20th Cent. (Medicine),Twentieth Century Histories,Twentieth Century History
D049674	History, 21st Century	Time period from 2001 through 2100 of the common era.	21st Century History,21st Cent. History (Medicine),21st Cent. History of Medicine,21st Cent. Medicine,Historical Events, 21st Century,History of Medicine, 21st Cent.,History, Twenty-first Century,Medical History, 21st Cent.,Medicine, 21st Cent.,21st Cent. Histories (Medicine),21st Cent. Medicines,21st Century Histories,Cent. Histories, 21st (Medicine),Cent. History, 21st (Medicine),Cent. Medicine, 21st,Cent. Medicines, 21st,Century Histories, 21st,Century Histories, Twenty-first,Century History, 21st,Century History, Twenty-first,Histories, 21st Cent. (Medicine),Histories, 21st Century,Histories, Twenty-first Century,History, 21st Cent. (Medicine),History, Twenty first Century,Medicines, 21st Cent.,Twenty-first Century Histories,Twenty-first Century History