To evaluate, in the framework of translational studies, vaccine leads lost in the valley of death from the start of the SarsCovid19 pandemic to the first vaccine. Systematic review

Translational studies and translational research refer to a process that aims to take discoveries from basic sciences to develop effective actions for the benefit of the population. These studies have different stages and in this systematic review I will focus on the valley of death or translational gap ("translational bridge") of vaccine prospects lost in this statistical space, having as a timeframe the beginning of the Covid19 pandemic, until the approval of the first vaccine. I will use the clinicaltrials.gov search engine to track studies from phase 1, considering that the common starting point for all studies is the discovery of a new coronavirus until phase 4. Phase I the average of the JADAD Scale obtained is 3.6, Phase II 3.1 on average and Phase III 3.3. In these studies, other scales are used to measure methodological quality, since their inability to significantly predict the progression of vaccine leaflet studies suggests that other factors may be influencing decision making to advance to subsequent clinical phases