Dialogue of an Almanac-Pedlar and a Passer-by

January unavoidably brings predictions. Old and new media rival one another to publish forecasts and more mundane prophecies around the new year; old-fashioned horoscopes, scientific foresight, experts’ opinions, they all work well in January. No one would be willing to replicate without any change even one of the last twenty years of his life -ironically noticed Giacomo Leopardi in his Dialogue of an Almanac-Pedlar and a Passer-by –we all prefer a future at random, although it is very unlikely that the future will be happier than the past.

A special class of new year predictions regards medical breakthroughs.  There are many of these medical predictions (including politically oriented ones); one of the most accredited is a list published, since 2010,  by a panel of physicians and scientists convened by Cleveland Clinic.  These  Top 10 Medical Innovations are announced in October, but  they are usually “re-discovered” and amplified in January. In 2018, they include in order of relevance, 1)  Hybrid Closed-Loop Insulin Delivery System; 2) Neuromodulation to Treat Obstructive Sleep Apnea; 3) Gene Therapy for Inherited Retinal Diseases; 4) The Unprecedented Reduction of LDL Cholesterol; 5) The Emergence of Distance Health; 6) Next Generation Vaccine Platforms; 7) Arsenal of Targeted Breast Cancer Therapies; 8) Enhanced Recovery After Surgery; 9) Centralized Monitoring of Hospital Patients; 10) Scalp Cooling for Reducing Chemotherapy Hair Loss.

Ranked only sixth in this list, “Next Generation Vaccine Platforms”  is thus considered less significant than, e.g., “Neuromodulation to Treat Obstructive Sleep Apnea” and “Unprecedented Reduction of LDL Cholesterol”; families involved in  5 million child deaths, worldwide caused, still  in 2016, by communicable and infectious diseases,  would probably disagree. The real issue is not, however, in this cliched comment (families could be finally wrong from a global perspective), rather in what the panel describes as a medical breakthrough. According to the Cleveland Clinic panel “in 2018, innovators will be upgrading the entire vaccine infrastructure to develop new vaccines more rapidly and break ground on novel mechanisms to better deliver vaccines to vast populations (…)  Companies are finding faster ways to develop flu vaccines using tobacco plants, insects, and nanoparticles. Oral, edible and mucosally delivered vaccines, intranasal vaccines, and vaccine chips are being developed. In 2018, a bandage-sized patch for flu vaccine is expected to be on the market. These new ways of developing, shipping, storing and vaccinating are anticipated to help stave off current and future diseases and epidemics”. Similar arguments are also proposed by Innovation House in its list of 2018 top medical breakthroughs, ranking “Next generation vaccination” 5^th; by the list provided by Health24, which ranks “Next-generation vaccines” 9^th; and even by the list of 2018 technology breakthrough proposed by MIT Technology Review.  All these arguments are based on old rhetoric expedient – first described by Aristotle – called “enthymeme,” an argument in which a critical supporting fact is omitted or only implicitly suggested.  If one looks more in-depth, the argument about next-generation vaccines first states that significant technical innovations in vaccines are expected in 2018; second, it affirms that this will dramatically contribute to avoiding infectious diseases and epidemics; what is missed? An explicit statement about the relationship between “new ways of developing, shipping, storing, and vaccinating” and the occurence of diseases, in real human, environment, and zoonotic communities. The argument takes as granted that this relationship is linear, while it is not. 

Vaccines are hardly drugs aiming to cure an individual; they are a way to modify the state of immunization of a population. A vaccination campaign fight against an infectious disease by increasing the number of hosts who are resistant (immune) to the particular microorganism that produces the disease in a community.   This modification is not a goal per se, rather it is instrumental to prevent, control, or eliminate the infectious disease. More targeted, better distributed, easily delivered, vaccines, are welcome, but 1) we know that this is only an element, hardly the most important one, in real life vaccination; 2)  there are several critical societal, economic, cultural, variables that are more important in determining failure or success of vaccination campaigns; 3) ultimately, the relationship between infections and diseases is rather complex, in many cases it is very difficult to predict from modifications of the immunity status of a population, the real evolution of  the  disease. Vaccines do not provide any certainty to the single individual, because individual immune response depends on the whole of host-pathogen interaction, including the overall health conditions, state of nutrition, pathogenic variability in hosts, the germ loads, and so.  The mere fact that one has been vaccinated does not guarantee against developing the disease – as well as it is not the sole possibility to avoid it; further preventive measures are always necessary, they are sometimes even more important than vaccination. Failing to communicate this central tenet could easily jeopardize any vaccination campaign.

Vaccinations have two possible objectives: 1) the elimination, or 2) the containment of the disease.  Elimination means full removing of the disease and its causal agent from a geographical area. Elimination requires universal vaccination, which is very difficult to achieve and could be even risky at the individual level. For instance, universal infantile vaccination raises the age in which the disease appears (“building up of susceptible”), and some infectious diseases may have a more severe course in adulthood (e.g., mumps), with a grave impact on population health. Moreover, the objective to drastically raise the “herd immunity,” inherent to any infectious elimination campaign, depends on many factors falling outside vaccine technology, such as modes of transmission, interspecies transmission, the degree of genetic and antigenic variation, and so. If these concepts are not communicated and well understood, vaccines could raise excessive expectations, easily followed by disillusionment and skepticism. Containment aims instead to reduce morbidity and mortality to “acceptable” levels.   In such, more frequent, cases, selective vaccination of groups and individuals is the most appropriate strategy. Also, with containment, communication strategies are thus a critical variable, because targeted groups and individuals should be convinced to take a preventive measure (vaccination), which is not asked to the majority of the population.

In conclusion, if the objective of medical breakthroughs should not be mere modifications of some biological parameters, but the real health conditions of a human population, it would have made more sense to consider current trends on data science and predictive analytics to influence individual and collective behaviors. Like it or not, they are the real breakthrough which is promising to change, for good or bad, the global vaccination scenario in 2018 and further.