Vaccines and Public Health
July 1st, 2010 | 
Author: 
For many centuries, especially from the formation of cities, people lived at the mercy of epidemics. Around 400 BC, Hippocrates distinguished between the diseases that usually affect populations (endemeion) of the “visiting” from the outside (epidemeion), defining and differentiating epidemic, as an objective of the realidad.1 For Moreover, in the biblical book of Revelation (circa 100 AD) is described as one of its four fearsome riders, the Plague, (a) hierarchy as one of the scourges of humanity, inevitable and inexplicable.
The development of the first vaccine in the West, 2 applied by Edward Jenner in England in the eighteenth century, introduced the first instrument to deal with epidemic diseases. The smallpox inoculation technique was applied in China many centuries ago. Jenner’s proposals were supported and financed by the wife of a British diplomat who had seen the technique in that country. The development of nineteenth century science allowed us to learn the characteristics and modes of transmission of infectious diseases, allowing the development of preventive tools, among which the most impact were drinking water and vaccinations.
In Argentina, there was in the early 60′s a big increase in value of vaccines, probably due to the coincidence in time of the polio epidemic of 1956 to 1957 and the emergence of the first vaccines for the disease (1955 Salk, Sabin 1960).
In the early days, immunization activities were carried out in campaign activities. Here, intense and limited in time, had much popular acceptance, so far as alternatives are proposed to address various problems. At that time, preventive medicine, who was born as an independent discipline in the late nineteenth century, began to approach the medical care, as was proposed as integrative medicine. The discipline more forcefully incorporated this model of patient care was of Pediatrics, possibly under the influence of the current led by Dr. Florencio Escardó. This coincided with a change in the mode of use of vaccines that happened to be scheduled and evaluation of coverage achieved.
The Different Logics
The incorporation of the vaccine as part of clinical services reinforced the idea of the vaccine as a tool for care and protection for the individual who received it, incorporated the concept of missed opportunities, and moved the objective coverage “to go out to all “to” be alert when they come. ” This allowed a greater role and ownership of the population in the field. Although this approach may have weakened the systemic action, this did not happen, possibly by a strong immunization program, even with some flaws, has been one of the most rational and sustained Argentine health programs.
Public Health, immunization is not only an act of personal protection, but a strategy to hinder or disrupt the circulation of the agent, providing protection to the entire community and not just recipients. To achieve this effect, the actions of ben be synergistic, (b) matching in the proposal and in time. Moreover, the evaluation does not end the patient’s card, but includes coverage achieved in the population and the impact (in reducing the disease).
The Epidemic Theory
The mechanics of epidemic transmission studied by Joseph Pannum3 interpersonal and systematized through the theory of Reed and Frost4 epidemic is characterized by the presence of an initial case, which makes contact with a certain number of individuals (contacts) in case of susceptible acquire the disease and, in turn, re-transmit to their own contacts, an increase in the rate of spread, because the number of “contagious” is growing. Only begin to decline when its spread among contacts of each case begins to increase the proportion of immune, protected by having had the disease in the first stage of the epidemic (or in earlier epidemics.) Epidemics do not affect the entire population, but in general, except for some subject that came into contact with any case for reasons of chance or because all their contacts were immune. This means an immediate benefit, although a future risk, since the accumulation of susceptible individuals over time involves the risk of providing a future epidemic because of its high proportion in the population.
The Intervention of Immunizations
The application of vaccines can transform susceptible to immune without having to suffer the disease. With this event we managed to increase the proportion of immune in a social group and, in particular, between the contacts of any case, difficult to spread. As they get better coverage are a number of effects:
1. Decrease of cases in each epidemic.
2. Interepidemic wider spacing. Having increased the immune, the accumulation of the proportion of susceptibles necessary to permit the emergence of an epidemic will require more time (see graph). Due to the lower frequency, the age range is extended and includes older ages (age shift) 6 This situation, according to the severity of each disease in relation to age, may be beneficial (H. influenzae) or dangerous (rubella .)
3. Control or elimination. It achieves the goal of having no case of disease through the disruption of interpersonal transmission (circulation of the agent) or a high security risk to disease continuum (tetanus). This situation creates a permanent risk of readmission, for which high coverage must be maintained (usually wane with the disappearance of the problem) and have intensified epidemiological surveillance to detect early re-entry.
4. Eradication. It consists of the global elimination of the use of the agent. It is the ultimate goal in the fight against disease, but is only possible where the reservoir is uniquely human and which has eficaz.5 vaccine