The twentieth century possesses an ever-increasing number of programs to prevent morbidity and mortality from specific infectious diseases in low- and middle- income countries. One of the main strategies employed is the utilization of DPT vaccination, which is primarily the alleviator of the condition diphtheria, pertussis and tetanus (Merson, 2004 p. 140). Routine primary immunization with DPT vaccine is given 2, 4, and 6 months with fourth dose at 15 months and a booster at 4-6 years before entry into school (Evans & Brachman, 1998 p. 58).
In general, DPT vaccine is administered to cover the three principal diseases, specifically diphtheria, pertussis and tetanus, at once. Such characteristic prevents multiple immunization programs and procedures especially for children. In addition, the efficiency of effect is more presently stabilized since the act of triple administration also produces triple effect; hence, in the course application of the overall immunization program, the child is protected at once after its completion. However, there are cases wherein these vaccine components are being separated in order to provide necessary individual treatment.
For instance, the serum antibodies for pertussis and tetanus are still active, while antibodies for diphtheria are no longer adequate to supply necessary protection; hence, diphtheria vaccination is deemed necessary, and in order to prevent costly and impractical service, individual diphtheria toxoids are necessary. Some 20% of adults or more may be unprotected against diphtheria and need either a full primary series or a booster dose of a preparation for adults or children more than 7 years old.
Booster doses of diphtheria toxoids are suggested for all adults every 10 years (Evans & Brachman, 1998 p. 58). Diphtheria vaccine is a formaldehyde-inactivated preparation of diphtheria toxin, absorbed onto a mineral carrier to increase antigenicity and reduce adverse reactions. Immunized individuals can be infected by toxin-producing strains of diphtheria but systemic manifestations of the disease do not occur (Mehta etal, 2004 p. 345). Diphtheria and tetanus vaccine are two commonly used toxoid-based vaccine preparations.
The combination of diphtheria and tetanus vaccine is possible, and usually applied to such cases wherein the individual is either immune to pertussis or the condition is not deemed as threat in the community. The initial stages of diphtheria vaccine production entail the growth of C. diptheriae. The toxoid is then prepared by treating the active toxin produced with formaldehyde. The product is normally sold as a sterile aqueous preparation. Tetanus vaccine production follows a similar approach wherein C.
tetani is cultured in appropriate media, the toxin is recovered and inactivated by formaldehyde treatment and marketed in aqueous form (Walsh, p. 440). On the other hand, there is no monovalent whole cell pertussis vaccine available in the current medical trend, but as an alternative, an Acellular Pertussis Vaccine (APV) is available on a named patient basis and, as with the dose of DPT, it is given by either deep subcutaneous or intramuscular injection.
Pertussis vaccine can be given when the pertussis component has been omitted from earlier immunizations. Although diphtheria is easier to diagnose than pertussis, it is likely that it is substantially under-reported in many low- and middle-income countries. Thus, the estimated 15,000-50,000 cases of diphtheria reported to WHO annually is the mid-1990s almost certainly do not reflect the actual burden of disease. Most cases of diphtheria occur in young children, primarily among those living in impoverished, crowded conditions.
Lack of vaccination is undoubtedly the most important risk factor for developing or dying from diphtheria (Merson, 2004 p. 147). The current approach to reducing morbidity and mortality from diphtheria is to improve levels of vaccine coverage achieved through ongoing infant immunization programs in various countries (Merson, 2004 p. 147). Vaccination protects against B. pertussis; however, worldwide count estimates 50 million cases of pertussis each year, resulting in almost 1 million deaths most especially in infants (Rubin & Strayer, 2007 p. 308).
The condition of pertussis is believed to be the cause of substantial morbidity and mortality in the absence of high levels of coverage with pertussis vaccine; however, it is difficult to assess the proportion of respiratory infections and related deaths due to pertussis. In part, this difficulty arises from the fact that many infants with pertussis never have the characteristic of whooping, which is normally seen in older individuals. Similarly, there is growing evidence that in industrialized countries and presumably in low-and middle-income countries as well, B.
pertussis is the cause of many cough illnesses in young adults that are never recognized as pertussis. Lastly, the laboratory diagnosis of pertussis has been plagued by the insensitivity, non-specificity, technical difficulty, and cost of the various diagnostic tests, making research studies difficult and routine surveillance extremely inaccurate. The current approach to reducing morbidity and mortality from diphtheria is to improve levels of vaccine coverage achieved through ongoing infant immunization programs in various countries (Merson, 2004 p. 147).