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Only a small proportion of people in many parts of the United States had antibodies to the novel coronavirus as of this spring, indicating most of the population remains highly susceptible to the pathogen, according to new data from the Centers for Disease Control and Prevention. The agency also reported the number of actual coronavirus infections is probably far higher — by two to 13 times — than reported cases. The higher estimate is based on the study on antibodies, which indicates who has had the virus in the past. Currently, the cumulative number of reported cases in the United States stands at 3.8 million. (McGinley, 7/21)

New research suggests that antibodies the immune system makes to fight the new coronavirus may only last a few months in people with mild illness, but that doesn’t mean protection also is gone or that it won’t be possible to develop an effective vaccine. “Infection with this coronavirus does not necessarily generate lifetime immunity,” but antibodies are only part of the story, said Dr. Buddy Creech, an infectious disease specialist at Vanderbilt University. He had no role in the work, published Tuesday in the New England Journal of Medicine. (Marchione, 7/21)

Aerosol samples collected from the hospital rooms of six COVID-19 patients in April contained infectious virus, adding to mounting evidence that the coronavirus is spread via aerosols in addition to large respiratory droplets, a non–peer-reviewed University of Nebraska study has found. The study, published yesterday on the preprint server medRxiv, identified RNA from SARS-CoV-2, the virus that causes COVID-19, on reverse transcription-polymerase chain reaction, which cannot discern whether the particles are infectious. But increases in viral RNA on cell culture showed significant growth of infectious virus in 3 of 18 aerosol samples after 5 or 6 days. Western blot and transmission electron microscopy also demonstrated evidence of intact virus. (7/21)

Of the 3,334 consecutive patients hospitalized with COVID-19 at a New York City hospital, 553 (16%) had thrombosis (blood clots), according to a research letter published yesterday in JAMA. Researchers at New York University Langone Health who analyzed the data of coronavirus patients hospitalized from Mar 1 to Apr 17 characterized the blood clots as deep vein thrombosis (DVT), pulmonary embolism (PE) and heart attack, ischemic stroke, and another systemic blood clot. (7/21)

One of the great mysteries of the coronavirus is how quickly it rocketed around the world. It first flared in central China and, within three months, was on every continent but Antarctica, shutting down daily life for millions. Behind the rapid spread was something that initially caught scientists off guard, baffled health authorities and undermined early containment efforts — the virus could be spread by seemingly healthy people. As workers return to offices, children prepare to return to schools and those desperate for normalcy again visit malls and restaurants, the emerging science points to a menacing reality: If people who appear healthy can transmit the illness, it may be impossible to contain. (Johnson, Sedensky and Choi, 7/22)

Six months into the pandemic, researchers are homing in on an answer to one of the basic questions about the virus: How deadly is it? Researchers, initially analyzing data from outbreaks on cruise ships and more recently from surveys of thousands of people in virus hot spots, have now conducted dozens of studies to calculate the infection fatality rate of Covid-19. (Abbott and Douglas, 7/21)

Scientists racing to develop a safe and effective COVID-19 vaccine are turning to what may seem like an odd ally: another family of viruses. At least five vaccine candidates are built on the backs of adenoviruses, a common family of pathogens that are often used as vehicles for delivering a variety of therapies to human cells. A sixth candidate uses a near relative of the family. (Wilson, 7/21)

While the race for a Covid-19 vaccine continues, scientists are learning more about the early vaccines used to fight smallpox, the only human infectious disease to be successfully eradicated. A new study published in Genome Biology on Sunday, carried out by scientists and historians from McMaster University, the Mütter Museum and the University of Sydney, identified five vaccine strains used by Civil War-era physicians to protect people from smallpox. (Giuliani-Hoffman, 7/21)

Kaiser Health News: Scientists Want To Know More About Using UV Light To Fight COVID-19 Spread 

High up near the ceiling, in the dining room of his Seattle-area restaurant, Musa Firat recently installed a “killing zone” — a place where swaths of invisible electromagnetic energy penetrate the air, ready to disarm the coronavirus and other dangerous pathogens that drift upward in tiny, airborne particles. Firat’s new system draws on a century-old technology for fending off infectious diseases: Energetic waves of ultraviolet light — known as germicidal UV, or GUV — are delivered in the right dose to wipe out viruses, bacteria and other microorganisms. (Stone, 7/22)

Hearts collected from nearly two dozen patients who died of coronavirus at University Medical Center are offering LSU researchers clues about how the disease affects vital organs, according to new research published Tuesday in Circulation, a journal of the American Heart Association. (Woodruff, 7/21)