The more we learn about this virus, the less there is to love. Via the South China Morning Post: Coronavirus that causes Covid-19 can produce more than three times as many pathogens than Sars strain, HKU study reveals. Excerpt:
The coronavirus that causes Covid-19 can produce more than three times the amount of pathogens than the strain that caused the severe acute respiratory syndrome (Sars) outbreak in 2003, although patients may display less inflammatory and immune responses, a study has found.
The finding from the research, led by prominent Hong Kong microbiologist Yuen Kwok-yung, is the first of its kind based on tests conducted on lung tissue removed from Covid-19 patients. The results underlined the virality of the disease, as well as difficulties for health authorities worldwide to detect it compared to Sars.
It took about six months to contain the Sars epidemic.
But it is a much bigger challenge for the Covid-19 pandemic, which has infected more than 1.6 million people around the world and caused more than 100,000 deaths in four months. According to the World Health Organisation, some 8,098 people were infected by Sars and 774 died of it.
“There is almost no possibility of containing the virus before July,” said Yuen, of the University of Hong Kong (HKU), who led the study published in the scientific journal Clinical Infectious Diseases.
By infecting lung tissues, donated by six patients, with both the viruses, Yuen and his team found the new coronavirus, officially known as Sars-CoV-2, generated 3.2-fold infectious viral particles than Sars within 48 hours.
“In some cases, Sars-CoV-2 could replicate by about 100 times within 48 hours, while the Sars virus may have peaked at about 10 to 20 times of replications,” Dr Chu Hin, research assistant professor from HKU’s medical school, said.
Despite reproducing more efficiently, the new virus induced slower immune and inflammatory responses, according to the study. Unlike the Sars virus, the Sars-CoV-2 almost did not induce any signalling protein interferons within 48 hours, which is key in triggering the immune system to counteract against the virus.
