Vaccinology in the third millennium: scientific and social challenges

Abstract

The epidemiology of deaths due to vaccine-preventable diseases has been significantly and positively altered through the use of vaccines. Despite this, significant challenges remain in vaccine development and use in the third millennium. Both new (Ebola, Chikungunya, Zika, and West Nile) and re-emerging diseases (measles, mumps, and influenza) require the development of new or next-generation vaccines. The global aging of the population, and accumulating numbers of immunocompromised persons, will require new vaccine and adjuvant development to protect large segments of the population. After vaccine development, significant challenges remain globally in the cost and efficient use and acceptance of vaccines by the public. This article raises issues in these two areas and suggests a way forward that will benefit current and future generations.

Figure 1

Challenges facing vaccines. (a) Pathogens for which we currently lack vaccines (HIV, M. tuberculosis, Ebola, SARS, MERS, among others). These are completely new pathogens that have not been studied, or are more complex pathogens with immunomodulatory traits or hypervariable genomes for which conventional vaccine development approaches have failed. (b) Re-emerging pathogens that current vaccines: have been unable to control or eradicate, elicit marginally protective immunity, have unwanted side effects (rotavirus), require multiple booster immunizations (hepatitis B), or require yearly vaccine reformulation (influenza). (c) Funding and regulatory issues can be formidable obstacles to the successful research, development, clinical testing, and licensure of new vaccines. These factors may also act as disincentives to even consider vaccine development. (d) Anti-vaccination groups are increasingly vocal in their opposition to vaccination. Current communication technologies allow them to rapidly and widely spread their messages against vaccines. As a result safety standards are considerably higher now and public opinion toward a new vaccine must now accurately gauged and considered to an extent never seen before. All images are public domain or are owned by their respective agency/foundation.

Figure 2

Solutions to the current vaccinology problems. (a and b) Cutting edge technologies allow investigators to study the immune system with unprecedented detail and scope. These technologies, along with novel analytical routines designed to handle the massive datasets, will provide greater insights into immune function and vaccine response. Studies targeting adjuvants and innate immune pathways will also be incorporated into the design of more effective vaccines, perhaps involving novel delivery systems such as the intradermal or intranasal routes pictured. (b) International partnerships that bring together scientific leaders from academia, product development expertise from industry, public health officials, and funding/support from private foundations and governmental agencies will be necessary to provide the stable, long-term support and resources necessary to create safe and effective vaccines. (c) Coordinated educational efforts that encompass multiple traditional and novel communication platforms will allow widespread delivery of scientific knowledge and data-driven findings. Physicians, healthcare providers, and patients will have open dialogs that acknowledge concerns and provide information tailored to the patient's preferred learning styles.