Vaccine impact: Benefits for human health

Abstract

Unlike most drugs, whose benefit is restricted to the individual who takes the drug, prophylactic vaccines have the potential for far-reaching effects that encompass health service utilisation, general health and wellbeing, cognitive development and, ultimately, economic productivity. The impact of immunisation is measured by evaluating effects directly on the vaccinated individual, indirectly on the unvaccinated community (herd protection), the epidemiology of the pathogen (such as changing circulating serotypes or prevention of epidemic cycles), and the additional benefits arising from improved health. Aside from protection of the individual, the broader success of immunisation is dependent on achieving a level of coverage sufficient to interrupt transmission of the pathogen. When evaluating the cost-effectiveness of vaccines, all of these potential benefits need to be accounted for. In many countries where immunisation programmes have been highly successful, the control of disease has meant that the benefits of immunisation have become less obvious. Once a well-known and much-feared disease appears to have disappeared, individuals, including healthcare professionals, no longer view ongoing prevention with the same sense of urgency. Reduced coverage is inevitably associated with resurgence in disease, with outbreaks potentially leading to significant morbidity and loss of life. Ensuring the continued success of immunisation programmes is the responsibility of all: individuals, healthcare professionals, government and industry.

Current state and challenges in developing oral vaccines

“…Vaccine efficacy is dependent on both the degree of protection conferred to individuals as well as the total coverage, accessibility, and costs associated with administering the formulation [2]. Vaccine distribution represents one of the main limiting factors in the impact of these prophylactic systems, particularly in developing nations with limited resources [27,28].…”

“…Immunization is a cost effective strategy that protects not only the vaccinated individuals, but can indirectly protect the surrounding community through the generation of herd immunity [2]. …”

“…The oral delivery of therapeutic drugs represents the current gold standard of therapeutic drug administration due to the opportunity for self-administration, improved patient compliance, and the ease of distribution compared to injection-based therapies [16–19]. Vaccine efficacy is highly correlated to its regional coverage, which is affected by the accessibility, stability, and distribution of the formulation [2,20]. Consideration of these parameters is important in the development of next-generation vaccines.…”

Early molecular correlates of adverse events following yellow fever vaccination

“…Smallpox and polio, which have collectively devastated millions of lives for centuries, have now been eradicated and eliminated in most parts of the world, respectively, through the widespread implementation of effective vaccines (1). Several other childhood or congenital diseases, such as measles, mumps and rubella, have also been controlled through vaccination programs.…”

Advances in Vaccines

“…During the largest Ebola outbreak in West Africa in 2014-2015, more than 28,000 cases were reported, and there occurred more than 11,000 fatalities. It is estimated that Guinea, Liberia, and Sierra Leone have endured more than US$2 billion loss in economic growth as a result of Ebola virus disease outbreaks [2]. Based on the experiences from West Africa Ebola epidemic outbreaks, the WHO published a prioritized list of 11 pathogens that likely to cause outbreak situations, including Ebola virus, Lassa virus, Marburg virus, MRSA, Zika virus, etc.…”