Costs vaccines

Finally, the vaccine must be inexpensive and this is by no means an easy requirement. To illustrate the point, if a vaccine costs 25 to produce, pack, and deliver to the patient, how can this be acceptable in a country where the amount of money available per patient is only 250 per annum Of course, money is saved on the subsequent savings in healthcare costs throughout the remainder of the patient s life. The rest of the debate is limited to a discussion of the value of a life, but in human terms this cannot be measured. 

A third example compared the cost in Sweden of treating patients who had had myocardial infarction with the P-blocker metoprolol. The direct health service costs for treatment were reduced from 17 120 to 12310 Swedish KrOner, a saving of 28%. A fourth example was used to justify hepatitis B vaccination in Japan. A net saving of 16 billion yen was estimated as a result of vaccination costing 1.3 bilUon yen. ... 

Riddiough MA, Sisk Je, BeU JC. Influenza vaccination cost-effectiveness and public policy. JAMA 1983 249 3189-3195. 

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. 

Rotavirus. Rotavims causes infant diarrhea, a disease which has major socio-economic impact. In developing countries it is the major cause of death in infants worldwide, causing up to 870,000 deaths per year. In the United States, diarrhea is stiU a primary cause of physician visits and hospitalization, although the mortaUty rate is relatively low. Studies have estimated a substantial cost benefit for a vaccination program in the United States (67—69). Two membrane proteins (VP4 and VP7) of the vims have been identified as protective epitopes and most vaccine development programs are based on these two proteins as antigens. Both Hve attenuated vaccines and subunit vaccines are being developed (68). 

Production of the vims in a bioreactor reactor, using a continuous cell line, has also been studied (85,86). This will reduce production costs and side effects. Both Madin-Darby canine kedney (MDCK) and Vero cell lines are being developed for production of the vaccine. 

Development of a peptide vaccine is derived from the identification of the immunodominant epitope of an antigen (141). A polypeptide based on the amino acid sequence of the epitope can then be synthesized. Preparation of a peptide vaccine has the advantage of allowing for large-scale production of a vaccine at relatively low cost. It also allows for selecting the appropriate T- or B-ceU epitopes to be included in the vaccine, which may be advantageous in some cases. Several vaccines based on peptide approaches, such as SPf66 (95) for malaria and an HIV-1 peptide (142) have been in clinical trials. No peptide vaccines are Hcensed as yet. 

Table 3. Benefit—Cost Analysis of Commonly Used Vaccines ...

Cost—benefit analyses for adult immunizations have also been performed. Influenza immunization during the period from 1971 to 1977 resulted in over 13 million more years of life at a cost of only 63 per year of life gained. Productivity gains were estimated to have a value of 250 x 10 (148). Projected costs of pneumonia have been calculated at 3.6 times the cost of vaccination, or a savings of 141 per person is achieved among those at risk for developing pneumonia or over the age of 50 years (149). 

BatteUe (MEDTAP) Eiual Report,M Cost Benefit Anafisis of DTP Vaccine to the U.S. Dept. Health and Human Services, Washiugtou, D.C., Mar. 4, 1994. 

Vaccines are a cost-effective means for disease prevention. It is estimated that for every dollar spent on routine childhood vaccines there will be a savings of 0.90 to 24.00 in direct medical expense. The rates of vaccination for children are well over 90%. This has been attributed to the requirements for proof of vaccination by states for enrollment into day care centers and school. Additionally, children (less than or equal to 18 years of age) may receive routine vaccinations free of charge through state health departments or other assistance programs, such as the national Vaccines for Children program. 

In addition, LS have several advantages over other delivery systems good physical stability, low cost of ingredients, ease of preparation and scale-up, and high entrapment yields for hydrophobic drugs. Moreover, LS have been successfully used both for the controlled delivery of various types of drugs and as carriers of vaccines and adjuvants [29,31,32]. 

Proteins such as antibodies, enzymes, hormones and vaccine antigens can be used to prevent, diagnose and treat a range of diseases. Such molecules are therefore of paramount importance in health and medicine. Historically, many of these proteins have been isolated from human or animal sources. However, the low quantities present in such source material coupled with safety risks and high purification costs have limited the availability of protein therapeutics and vaccines for many types of disease. 

The most widely studied therapeutic proteins produced in plants include monoclonal antibodies for passive immunotherapy and antigens for use as oral vaccines [40]. Antibodies against dental caries, rheumatoid arthritis, cholera, E. coli diarrhea, malaria, certain cancers, Norwalk virus, HIV, rhinovirus, influenza, hepatitis B virus and herpes simplex virus have been produced in transgenic plants. However, the anti-Streptococcus mutans secretory antibody for the prevention of dental caries is the only plant-derived antibody currently in Phase II clinical trials [40]. Until recently, most antibodies were expressed in tobacco, potato, alfalfa, soybean, rice and wheat [9], It has been estimated that for every 170 tons of harvested tobacco, 100 tons represents harvested leaves. A single hectare could thus yield 50 kg of secretory IgA [3, 41]. Furthermore, it has been estimated that the cost of antibody production in plants is half that in transgenic animals and 20 times lower than in mammalian cell cul-... 

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