The new SARS-CoV-2 coronavirus has spread rapidly around the world since it was first reported in humans in Wuhan, China, in December 2019 after being contracted from a zoonotic source. This new virus produces the so-called coronavirus 2019 or COVID-19. Although several studies have supported the epidemiological hypothesis that weather patterns may affect the survival and spread of droplet-mediated viral diseases, the most recent have concluded that summer weather may offer partial or no relief of the COVID-19 pandemic to some regions of the world. Some of these studies have considered only meteorological variables, while others have included non-meteorological factors. The statistical and modelling techniques considered in this research line have included correlation analyses, generalized linear models, generalized additive models, differential equations, or spatio-temporal models, among others. In this paper we provide a systematic review of the recent literature on the effects of climate on COVID-19’s global expansion. The review focuses on both the findings and the statistical and modelling techniques used. The disparate findings reported seem to indicate that the estimated impact of hot weather on the transmission risk is not large enough to control the pandemic, although the wide range of statistical and modelling approaches considered may have partly contributed to the inconsistency of the findings. In this regard, we highlight the importance of being aware of the limitations of the different mathematical approaches, the influence of choosing geographical units and the need to analyse COVID-19 data with great caution. The review seems to indicate that governments should remain vigilant and maintain the restrictions in force against the pandemic rather than assume that warm weather and ultraviolet exposure will naturally reduce COVID-19 transmission.

The use of probiotic starters remaining viable in unpasteurized and unfiltered beers could significantly increase health benefits. Here, the probiotic Saccharomyces cerevisiae var. boulardii (Sc_b) and a commercial Saccharomyces cerevisiae (Sc) strain, which is commonly employed in the brewing industry, are compared as single starters. The healthy value of the produced beers and growth performance in a laboratory bioreactor are analysed by determining antioxidant activity, phenolic content and profile, alcohol, biomass growth modelling by the logistic and Gompertz equations, biovolume estimation from 2D microscopy images, and yeast viability after fermentation. Thus, in this study, the craft beer produced with the probiotic yeast possessed higher antioxidant activity, lower alcohol content, similar sensory attributes, much higher yeast viability and more acidification, which is very desirable to reduce contamination risks at large-scale production. Furthermore, Sc_b exhibited faster growth in the bioreactor culture and larger cell volumes than Sc, which increases the probiotic volume of the final craft beer.