Читать книгу Basic Virology - Martinez J. Hewlett - Страница 46

Generation of lasting immunity provides an effective means of controlling and even eradicating certain viral diseases. The antigenic stability of the smallpox virus and effective immunity against it allowed effective vaccination programs to eradicate the disease from the population. Polio and measles are current candidates for partial or total elimination from the population due to availability of effective vaccines. In addition, currently a program is underway to try to vaccinate wild populations of raccoons and other small carnivores against rabies with use of vaccine‐laced bait. It is hoped that such an approach will reduce or eliminate the growing incidence of rabies in US wild animal populations. Of course, the reason for this solicitude has little to do with the animals involved; rather, it is to afford protection to domestic animals, and ultimately to humans.

Despite our considerable abilities, not all viral diseases can be readily controlled even under the most favorable economic and social conditions. Flu virus variants arise by genetic mixing of human and animal strains, and it is not practical to attempt a widespread vaccination campaign with so many variables. HIV remains associated with lymphatic tissue in infected individuals even when antiviral drugs effectively suppress virus replication. The intimate association of HIV with the immune system may make vaccination campaigns only partially effective. The ability of herpesviruses to establish latent infections and to reactivate suggests that a completely effective vaccine may be difficult if not impossible to generate.

A major obstacle to the control of viral and other infectious diseases in the human population as a whole is economic. It costs a lot of money to develop, produce, and deploy a vaccine. Many of the nations most at risk of deadly infectious disease outbreaks are financially unable to afford effective control measures, and pharmaceutical corporations involved with vaccine research and production are primarily interested in bottom‐line profit. Perhaps more tragically, some nations at risk also lack the political will and insight to mount effective efforts to counter the spread of viral disease. Such problems constantly change character but are never ending.