# Lessons Learnt from COVID-19: Computational Strategies for Facing Present and Future Pandemics
## 1 The COVID-19 Pandemic  
In December 2019, a cluster of pneumonia cases of unknown etiology emerged in the Chinese city of Wuhan [1]. Soon after, analyses of patients' lung fluid, blood, and throat swabs reconstructed this outbreak to a newly identified virus, tentatively named 2019-new coronavirus (2019-nCoV) [2].  
Phylogenetic analyses performed on viral genomes isolated from patients' samples revealed a close relationship between the new virus with several bat coronaviruses isolated in China (>90%). A lower degree of similarity was also found with SARS-CoV (80%) and MERS-CoV (50%), the causative agents of two recent coronavirus-related epidemics [3]. Based on phylogeny, taxonomy, and established practice, the virus was renamed SARS-CoV-2 [4], while the associated illness was defined as COVID-19 by the World Health Organization (WHO) [5].  
The striking similarity between the SARS-CoV-2 genome and several bat coronaviruses led to the hypothesis that bats could be the animal reservoir for SARS-CoV-2, with pangolins or other mammals acting as the intermediate host before human transmission [6]. The assumption that bats could be the animal reservoir of SARS-CoV-2 was further reaffirmed at a later stage by the work of [PERSON] et al., which identified in the caverns of North Laos a series of bat coronaviruses that share a high level of sequence similarity (96%) with the SARS-CoV-2 genome [7].  
From a clinical perspective, the spectrum of COVID-19 manifestation is broad, ranging from asymptomatic infections to severe viral pneumonia with respiratory failure and evendeath [8]. The most common symptoms, similar to influenza, are related to mild upper respiratory tract affection, such as fever, cough, myalgia, and headache [9]. Less common but still relevant ones include gastrointestinal manifestations, such as diarrhea, and more severe respiratory illnesses, such as dyspnea, and multiorgan failure [10].  
The long incubation time compared to similar infections [11], the capability of asymptomatic [12] or paucisymptomatic [13] patients to transmit the virus even before the eventual symptoms' manifestation, and the aerial transmission modality [14,15] all concurred to determine a higher transmissibility index (estimated between 2.5 and 3.0) for the SARS-CoV-2 virus, compared to similar viral infections [16]. These factors contributed to the rapid spread of SARS-CoV-2 worldwide, resulting in more than 650 million cases and more than 6.5 million deaths globally [17].  
In the first stages of the COVID-19 pandemic, extraordinary sanitary measures, such as physical and social distancing, wearing face masks, and eye protection devices [18,19] were adopted to prevent the collapse of the public healthcare system [20], due to the imbalance between the high demand and the low availability of critical supplies [21,22]. Although this short-term plan has proven helpful in gaining time [23,24], more sustainable and long-term oriented strategies were needed to better cope with the socio-economic [25] and psychological [26] consequences of the pandemic, other than ensuring fair and efficient resource management [27].