Una serie de noticias en Nature, incluyendo una que discute las diferencias notables entre el anuncio de Pfizer y la vacuna que están probando en Gamaleya. Where did COVID come from? WHO investigation begins but faces challenges.
Most researchers think the virus originated in bats, but how it jumped to people is unknown. Other coronaviruses have passed from an intermediate animal host; for example, the virus that caused an outbreak of severe acute respiratory syndrome (SARS) in 2002–04 probably came to people from raccoon dogs (Nyctereutes procyonoides) or civets. (...) Nailing down the origins of a virus can take years, if it can be done at all, and the investigation will also have to navigate the highly sensitive political situation between China and the United States. US President Donald Trump has been “calling it a China virus and the Chinese government is trying to do everything to prove that it is not a China virus”, says Linfa Wang, a virologist at Duke–National University of Singapore Medical School. The political blame game has meant that crucial details about research under way in China have not been made public, says Wang, who was part of the WHO mission that looked for the origin of SARS in China in 2003.Russia announces positive COVID-vaccine results from controversial trial.
The Gamaleya National Center of Epidemiology and Microbiology in Moscow and the Russian Direct Investment Fund said that an interim analysis of 20 COVID-19 cases identified among trial participants had found that the vaccine was 92% effective. (...) The Sputnik V trial’s protocol has not been made public, in contrast to those of Pfizer and some other leading candidates in phase III trials, so it is unclear whether an interim analysis after identification of just 20 COVID-19 cases was in the works. Pfizer had originally planned to do its first interim analysis after 32 cases, but changed course after discussions with the US Food and Drug Administration.Why do COVID death rates seem to be falling?
One shining light that he can point to is his intensive-care unit’s dwindling fatality rate. In April, up to 35% of those in the unit with COVID-19 perished, and about 70% of those on ventilators died. Now, the intensive-care mortality rate for people with the illness is down to 30%, and for those on ventilators it is around 45–50%. (...) The reasons are not entirely obvious. There have been no miracle drugs, no new technologies and no great advances in treatment strategies for the disease that has infected more than 50 million and killed more than 1.2 million around the world. Shifts in the demographics of those being treated might have contributed to perceived boosts in survival. And at many hospitals, it seems clear that physicians are getting incrementally better at treating COVID-19 — particularly as health-care systems become less overwhelmed. Still, those gains could be erased by increasing case loads around the world.