Evaluation of the Effectiveness & Demand for a New Vaccine
Assessing biological and programmatic effectiveness of a vaccine are important for wide use of the vaccine. Use of a standardized protocol in this regard will help the national programs implement and evaluate their programs and promote cross program learning. Financial planners need to know this information for introduction of the vaccine. The costs of the vaccine program can largely be anticipated since they include items that are reasonably known. These include purchase of the vaccine, personnel and transportation costs and communications and logistics cost. Costs of treating a patient with the vaccine-preventable disease can be determined from medical records. The more difficult costs to estimate are the costs of the disease in an outbreak situation. Typically, an outbreak leads to the disruption of health services with subsequent deterioration of other routine services. Further costs are related to effects on trade and travel. Cost–effectiveness calculations can also be influenced by the variations in target disease incidence from year to year. Since the cost–effectiveness calculation is related to the rate of the disease and the cost of the vaccine, the vaccine can be thought to have poor effectiveness when the disease incidence is low. However, since the vaccine program affects disease incidence, one must consider historical rates in the model and not just rates during the duration of the project.
The demand for a new vaccine is usually uncertain. Vaccine producers may not invest in initiating new vaccine production without an estimate of the potential demand. This has created a vicious circle in the past and has delayed the introduction of new and underutilized vaccines in developing countries. The uncertainty of demand has led to a reluctance among vaccine manufacturers to increase production resulting in a low supply and high prices.
The challenge to the global health community is to ensure that there is a predictable and growing demand, facilitated by donor funding and technical support, which could lead current vaccine manufacturers to increase their production capacity for the vaccine and possibly new manufacturers to enter the market. This would result in the growth of global production capacity, in turn leading to lower price of the vaccines. Note that financial and technical support from the GAVI Alliance and from several accelerated development and introduction plans have helped to create virtuous cycles for several newer vaccines in recent years, including hepatitis B, the pentavalent (DPT-HepB-Hib) and rotavirus vaccines.
Rational and effective use of the vaccine may also lead to an increased demand of the vaccine that may spur increased vaccine production. Consequently, there is a need to conduct research and evaluation of the vaccine introduction programs to increase the demand for vaccine. The program should include providing technical assistance, and focusing operations research to know how to overcome the barriers to introducing a new vaccine as well as achieving a good coverage of the vaccine. Dissemination of the important findings from introducing of a new vaccine in a developing country is also important for broader acceptability of the vaccine. Developing a forecast of the demand for vaccines provided through public health sector programs in developing countries is critical to encourage existing producers to invest further in their vaccine production capacity, as well as new manufacturers to acquire the technology to produce the vaccine. Vaccination coverage remains unsatisfactory in many parts of the world, often due to lack of funding and infrastructure, but also due to political and/or economic instability.