In biotechnology originated for their potential applicatons in health care of both human and animal but primarily the former. It is in this sector that the contribution of biotechnology are most frequent more notable and that whole gamut of contributions in text of limited space these could be grouped under the following broad heads (1) disease prevention (2) therapeutic agents (3) fertility control of these categories bu citing appropriate examples. (4) forensic medicine is is aimed to highlight the major developments under each of these categories by citing appropriate examples.
Disease prevention vaccines. It is the most desirable most convenient and highly effective approach to health this achieved by vaccination or immunization using biological preparations called vaccines. Vaccines represent invaluable contribution biotechnology they provide protection against even such for which effective cures are not yet available.
An ideal vaccine should have the following features.
(1) It should not be tumerogenic or toxic or pathogen.
(2) It should have very low levels of side effects.
(3) It should not spread either within the vaccinated individual or to other individuals.
(4) It should be effective in producing long lasting hormonal and cellular immunities.
Conventional vaccines. Conventional vaccines consist of whole pathogenic organisms which may either by killed or live the virulence of pathogens is greatly reduced most viral vaccines conventional vaccine is highly effective having the following features
(1) In many case live vaccines have to be used since killed pathogen vaccines are ineffective.
(2) Live vaccines are generally based on cultured animal cells, hence expensive tissue culture set up is essential.
(3) Live vaccines are heat labile due to the pathogen inactivation by heat.
(4) Conventional vaccines carry a variable risk of disease development due to the occasional presence of active virus particles or reversion to virulence after replication in the vaccinated individual.
Purified antigen vaccines. These vaccine are based on purified antigens isolated from the concerned pathogen they donot contain the organism the risk of pathogenicity is avoided their cost is higher to the steps involved in purification and vaccince preparation and many of the isolated antigens are poorly immunogenic.
Many bacteria produce exotoxins which are highly immunogenic but these toxins produce toxic effects the intensity of which decreases with storage and this decline is accelerated by heat formaldehyde and other chemicals. Some toxic are ery good adjuvants increase the immunogenicity of other antigens for example diptheria toxoid for example the B polysaccharide of Haemophilus influenzae ispoorly immuogenic. But when the B polysaccharide is combined with the diptheria toxoid its immunogenicity in greatly increased in many cases such adjuvant activities can be used to great advantage since most of the isolated antigens from pathogens are poorly immunogenic.