Modeling of SARS-CoV-2 spread in Hunan, China showed that a minority of people infected with COVID-19 transmitted most infections. More than half of infections were spread before infected people developed symptoms. The findings could help inform better policies to control the spread of COVID-19 while balancing economic impact.
The coronavirus SARS-CoV-2 is transmitted predominantly through the air — by people talking and breathing out large droplets and small particles called aerosols. Catching the virus from surfaces — although plausible — seems to be rare. Despite this, some public-health agencies still emphasize that surfaces pose a threat and should be disinfected frequently. The result is a confusing public message.
Link to article: https://www.nature.com/articles/d41586-021-00277-8
A new study of more than a half-million people in India who were exposed to the novel coronavirus suggests that the virus’ continued spread is driven by only a small percentage of those who become infected, known as superspreaders. The study also found that children and young adults are potentially much more important to transmitting the virus than previously thought. The paper is the largest COVID-19 contact-tracing study to date.
A paper in the New England Journal of Medicine reports on a trial of 45 healthy adults aged 18-55, each vaccinated twice, 28 days apart, with the mRNA-1273 vaccine developed by the National Institute of Allergy and Infectious Diseases (NIAID) and pharmaceutical company Moderna. All participants subsequently produced antibodies against the SARS CoV-2 virus, and their blood serum showed neutralizing activity against the virus, preventing it from entering cells. Moreover, the vaccine appears to provide stronger protection against new infections than an average bout of actually catching the disease.
Converging lines of evidence indicate that SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, can pass from person to person in tiny droplets called aerosols that waft through the air and accumulate over time. An international group of 237 clinicians, infectious-disease physicians, epidemiologists, engineers, and aerosol scientists have published a commentary in the journal Clinical Infectious Diseases that urges the medical community and public health authorities to acknowledge the potential for airborne transmission. They also call for preventive measures to reduce this type of risk.
This study looks at certain genetic variations in people that are associated with susceptibility to infection and the diverse clinical presentation of coronavirus disease (COVID-19) – including asymptomatic cases and severe forms of the disease in younger patients.
New paper shows that when exposed to the MERS Coronavirus (CoV) bat cells adapt—not by producing inflammation-causing proteins but rather by maintaining a natural antiviral response. Simultaneously, the MERS virus also adapts to the bat host cells by very rapidly mutating one specific gene. Operating together, these adaptations result in the virus remaining long-term in the bat but being rendered harmless. Instead of killing bat cells as the virus does with human cells, the MERS coronavirus enters a long-term relationship with the host, maintained by the bat’s unique ‘super’ immune system. SARS-CoV-2 is thought to operate in the same way. The work suggests that stresses on bats—such as wet markets, other diseases, and possibly habitat loss—may have a role in coronavirus spilling over to other species.
Link to paper: https://www.nature.com/articles/s41598-020-64264-1
New genetic analysis of SARS-CoV-2 and related coronaviruses suggests the ancestor of COVID-19 and its nearest relative — a bat coronavirus — infected the intestine of dogs, most likely resulting in a rapid evolution of the virus and its jump into humans. This suggests the importance of monitoring SARS-like coronaviruses in feral dogs. It is to be noted however that other experts have doubts.