Exposure to one nasal droplet enough for Covid infection – study Trial in which volunteers were given dose of virus is first to monitor people during entire course of infection https://www.theguardian.com/world/2...asal-droplet-enough-for-covid-infection-study Exposure to a single nasal droplet is sufficient to become infected with Covid-19, according to a landmark trial in which healthy volunteers were intentionally given a dose of the virus. The trial, the first to have monitored people during the entire course of infection, also found that people typically develop symptoms very quickly – on average, within two days of encountering the virus – and are most infectious five days into the infection. The study was carried out using a strain of the virus before the emergence of the Alpha, Delta and Omicron variants. The trial’s chief investigator, Prof Christopher Chiu, of Imperial College London, said: “Our study reveals some very interesting clinical insights, particularly around the short incubation period of the virus, extremely high viral shedding from the nose, as well as the utility of lateral flow tests, with potential implications for public health.” The findings, published on Springer Nature’s pre-print server, and which have not yet been peer-reviewed, detail the outcomes in 36 healthy, young participants with no immunity to the virus. The volunteers were monitored at a specialist unit at the Royal Free hospital in London, and experienced no severe symptoms. The study found that the infection first appears in the throat and that infectious virus peaks about five days into infection, by which point the nose has a much higher viral load than the throat. The study also suggested that lateral flow tests are a reassuringly reliable indicator of whether infectious virus is present. Swabbing the nose and throat makes it more likely to detect infections during the first few days, the work suggests. “We found that overall, lateral flow tests correlate very well with the presence of infectious virus,” said Chiu. “Even though in the first day or two they may be less sensitive, if you use them correctly and repeatedly, and act on them if they read positive, this will have a major impact on interrupting viral spread.” The study also revealed that of the 18 people who became infected, all had similar viral loads regardless of whether they developed symptoms, underlining the role of asymptomatic transmission. Prof Wendy Barclay, the head of the department of infectious disease at Imperial College London, said: “A lot of people could be walking around shedding virus and not realising. It’s really marked with this virus.” Intriguingly, some of those who did not meet the threshold for being infected also had very low levels of virus detectable in their noses and throats, suggesting that they may have experienced a very short-lived infection that was seen off by immune activity in the lining of the nose and throat. The team are expected to publish further findings giving a unique window into the earliest phase of the immune response, during the first hours and days after encountering the virus. The team say the trial paves the way for future challenge studies that could help accelerate the development of the next generation of vaccines and antiviral drugs. Phase 3 studies have become increasingly difficult to plan due to the erratic levels of transmission in the population. Challenge studies are far quicker and require far fewer participants to establish efficacy. Prof Sir Jonathan Van-Tam, the deputy chief medical officer for England, said: “Scientifically, these studies offer real advantage because the timing of exposure to the virus is always known exactly, therefore things like the interval between exposure and the profile of virus shedding can be accurately described. “This important study has provided further key data on Covid-19 and how it spreads, which is invaluable in learning more about this novel virus, so we can fine-tune our response.”
Controversial study in which volunteers infected with Covid delivers first results Research shows that average time from first exposure to viral detection and early symptoms was 42 hours, significantly shorter than existing estimates https://www.independent.co.uk/news/...uman-challenge-infected-results-b2005928.html
Some provinces in Canada and many states in the United States are seeing their Covid hospital numbers and infections starting to decline dramatically... As announced early in January that Canada is removing/easing its mandates on February 14th (Quebec) and others doing the same over the next few days. This is not a government (federal) decision... it's a provincial / state decision to either keep the mandates a little longer or to remove/ease the restrictions. Yet, they all say that if a new Variant of Concern shows up again...the restrictions will come back. Personally, I saw things back to normal in my area by January 8th when I enter a Pharmacy and those hand sanitizers were not at the entry door, no more 6ft reminder strips on the floor and I saw a few people in the pharmacy without their face mask on their face...just around their neck. Time for the majority that is vaccinated to move on and good luck to the minority that is not vaccinated or can not be vaccinated. wrbtrader
Covid impacts more than male fertility. For months medical researchers have been looking in to significant increase in stillbirths among unvaccinated women. It turns out that being unvaccinated drastically increases the probability of having a stillbirth if the mother contracts Covid. Coronavirus can destroy the placenta and lead to stillbirths https://apnews.com/article/coronavirus-pandemic-science-health-2ac91326c0cd16f67eba01885516ef2d New research suggests the coronavirus can invade and destroy the placenta and lead to stillbirths in infected women. It’s an uncommon outcome for any pregnancy but women with COVID-19 face an elevated risk. Authorities believe vaccination can help prevent these cases. Researchers in 12 countries, including the United States, analyzed placental and autopsy tissue from 64 stillbirths and four newborns who died shortly after birth. The cases all involved unvaccinated women who had COVID-19 during their pregnancy. The study bolsters evidence from small case reports and it confirms that placenta damage rather than an infection of the fetus is the likely cause of many COVID-19-related stillbirths, said Dr. Jeffery Goldstein, a pathologist at Northwestern University’s Feinberg School of Medicine. He was not involved in the study, which was published Thursday in Archives of Pathology & Laboratory Medicine. Previous evidence suggests the chances of stillbirth are higher than usual for pregnant women with COVID-19, particularly from the delta variant. Vaccination recommendations include pregnant women and note their higher risk for complications when infected. Lead author Dr. David Schwartz, an Atlanta pathologist, said other infections can infiltrate the placenta and cause stillbirth, typically by infecting and damaging the fetus. A recent example is Zika virus. He and his colleagues wanted to see if that was the case with stillbirths in women with COVID-19. But what they found was almost the opposite: it was the placenta that was infected and extensively destroyed. “Many of these cases had over 90% of the placenta destroyed — very scary,” said Schwartz. Normal placenta tissue is a healthy reddish hue and spongy. The specimens they studied were stiff, with dark discolorations of dead tissue. While other infections can sometimes damage the placenta, Schwartz said he’d never seen them cause such consistent, extensive destruction. The placenta is an organ that forms and attaches to the womb during pregnancy. It connects with the umbilical cord, providing oxygen and nourishment from the mother’s bloodstream. The virus likely reached the placenta through the bloodstream, attaching to susceptible cells and causing protein deposits and an unusual form of inflammation that blocked blood flow and oxygen. That in turn led to placenta tissue death and suffocation, the researchers said. Coronavirus was also detected in some of the fetuses, but evidence of suffocation in the womb points to placenta damage as the more likely cause of death, they said. A Centers for Disease Control and Prevention report in November found that among pregnant U.S. women infected with COVID-19, about 1 in 80 deliveries was a stillbirth — the loss of a fetus anytime after 20 weeks. That’s compared with 1 in 155 among uninfected women. The study stillbirths occurred on average at 30 weeks; normal pregnancies last about 40 weeks. High blood pressure, certain chronic illnesses and fetal abnormalities are among conditions that can increase chances for stillbirths, including in women with COVID-19. It is unclear whether omicron infections also increase chances for stillbirths; the study was done before that highly infectious variant emerged.
What's the website source for the graphs ? I had similar graphs but lost the link to the site that I wanted to post about another issue involving the usefulness of vaccines and face mask wear for the three particular Covidiots that keep posting slime dribble, misinformation, disinformation that vaccines do not work... Then they will say that they're not against vaccines but are only against mandates. Wonderfully, many countries now no longer have mandates and easing restrictions and they're still playing the same tune about their lost freedom although the live in a different country. wrbtrader
Until we get 70% of people vaccinated in every country... Covid has no chance of becoming an endemic. 'It ain't over:' COVID-19 won't become an endemic until the world is vaccinated https://toronto.ctvnews.ca/it-ain-t...demic-until-the-world-is-vaccinated-1.5783291
Vaccine-induced antibodies more effective than natural immunity in neutralizing SARS-CoV-2. The mRNA vaccinated plasma has 17-fold higher antibodies than the convalescent antisera, but also 16 time more potential in neutralizing RBD and ACE2 binding of both the original and N501Y mutation