LONDON : Scientists have described three distinct phases of COVID-19 disease progression in patients, urging medical professionals to consider an individualised treatment approach for patients based on their symptoms corresponding to these stages of infection.According to the scientists, including those from the University of Florence in Italy, three distinct phases of COVID-19 infection, with variable degrees of symptoms have been observed in people who test positive for the deadly disease.The review research, published in the journal Physiological Reviews, noted that each of these phases is characterised by a different type of biological interaction with the virus.SARS-CoV-2, the novel coronavirus that causes COVID-19, is transmitted.