Study: How effective does a COVID-19 coronavirus vaccine need to be to stop the pandemic?

‘In a study published July 15 in the American Journal of Preventive Medicine, my colleagues and I used a computer simulation of every person in the country to show how effective a vaccine would have to be and how many people would have to get vaccinated to end the pandemic. We found that a coronavirus vaccine’s effectiveness may have to be higher than 70% or even 80% before Americans can safely stop relying social distancing. By comparison, the measles vaccine has an efficacy of 95%-98%, and the flu vaccine is 20%-60%….’

— via The Conversation

Your best view in 6800 years

Above Kreva, Belarus on July 13, 2020. 

‘For the next month, comet C/2020 F3 (NEOWISE), otherwise known as “Neowise,” will be visible in the night sky above much of the Northern Hemisphere. The comet will be at its brightest this week, dimming as it moves away from the sun. If you have clear skies, head outside about an hour after sunset and look near the horizon to the northwest. For the next week or so, if it’s dark enough, Neowise might be visible to the naked eye, but you may need binoculars to see it well. The images in the photos below are made with long exposures, so they may appear stronger than what you’d see with your own eyes, but it’s still worth a look—this is the brightest comet we’ve seen in 23 years, and after this, Neowise won’t be back for another 6,800 years….’

— via The Atlantic