Coronavirus (COVID-19) Collection
- Natural SARS-CoV-2 infection elicits humoral (Percivalle et al., 2020; Ni et al., 2020; Muecksch et al., 2021) and cellular responses (Grifoni et al., 2020). However, little is known about protection against secondary infection. Recently, a longitudinal study conducted in the United Kingdom (Lumley et al., 2021) showed that SARS-CoV-2 seropositivity was associated with a lower SARS-CoV-2 RNA detection rate.
- Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), was first reported in China in December 2019. As of February 21, 2020, more than 7,151,000 cases of COVID-19 have been reported worldwide and there are more than 407,145 deaths. The spread has already taken on pandemic proportions, affecting over 100 countries, including Italy that counts more than 235,270 cases (Ghinai et al., 2020; Remuzzi and Remuzzi, 2020). In February 2020, a large COVID-19 outbreak in Lombardy Italy was observed.
- In Italy, the first wave of the coronavirus disease 2019 (COVID-19) pandemic mainly hit the northern regions with critical consequences, particularly for the elderly population. Residents in nursing homes, often affected by multiple comorbidities, are at greater risk of serious – potentially fatal – disease (Liu et al., 2020). It has been observed that elderly patients with COVID-19 often do not present classic symptoms (such as fever or cough), but can have an atypical course of disease (such as delirium, abdominal pain and low-grade pyrexia) (Tay and Harwood, 2020).
- On February 20, 2020, Lombardy, a region in northern Italy, was struck by an outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Soon afterward, the epidemic involved other Italian regions, with a north-south gradient. Several containment measures were adopted, including lockdown of affected areas, social distancing, and quarantining of individuals with laboratory-confirmed COVID-19 as well as their close contacts. Laboratory confirmation of SARS-CoV-2 infection relied on positivity of a nasopharyngeal swab on virus-specific real-time reverse transcription PCR (RT-PCR) targeting several SARS-CoV-2 genes (Centers for Disease Control and Prevention, 2020; WHO, 2020a; Wang et al., 2020).