June 8, 2022 - Podcast

Episode 277 — COVID-19 in China, and a prehistoric look at genomic evolution

An IU public health researcher is part of a team of scientists in China and the U.S. who've issued grim predictions if China abandons its Zero-COVID Policy. Associate Professor Marco Ajelli and his collaborators recently published a study in Nature Medicine modeling the transmission of SARS-CoV-2, the virus that causes COVID-19, in China. The authors assert that in the absence of strict protective measures, the highly contagious omicron variant of COVID-19 would likely kill 1.5 million people in China within a very short period. Ajelli says the study shows that a COVID-19 outbreak of this size would overwhelm the Chinese health care system, particularly the intensive care units. He says if there is a bed shortage due to a sharp increase in COVID-19 cases, other people requiring critical care won't have access to it, further increasing the number of likely deaths. Only about half the people in China over age 80 are vaccinated against COVID-19. Ajelli says improving vaccination rates, especially among the elderly; increasing access to antiviral therapies; masking; and other non-pharmaceutical interventions could be sufficient to prevent overwhelming the Chinese health care system, suggesting that these factors should be points of emphasis in future mitigation policies. Regardless of whether the country eliminates zero-COVID practices, he says these strategies are critical to slowing the pandemic in China.

In other news, a new study by IU researchers gives a prehistoric look at genomic evolution, with potential impacts for research on genetic diseases. The study was recently published in Nature Microbiology. Led by Molecular Biologist Stephen Bell, the researchers found that in archaea, the shape of a DNA molecule can affect its ability to change. This means that over time, form is actually influencing evolution. Archaea are single-celled microorganisms discovered in the 1970s. They are one of the three domains of life on Earth, which scientists use to classify all life forms. The other two domains are bacteria and eucaryotes, which include mammals and humans. Archaea is possibly the most ancient domain of the three. Bell says you can think of archaea as molecular fossils because studying them is like getting in a time machine and looking back about 2 billion years. Previous research by Bell and his collaborators found that certain species of archaea organize their chromosomes, which store DNA, into two compartments. For this new study, IU researchers measured mutation rates of chromosomes in 11 species in a certain genus of archaea. Their analysis demonstrated that the DNA in one compartment changed at a much faster rate than the other compartment. Bell says the discovery is important because understanding the form and function of DNA may help researchers better understand all life forms, including humans. That knowledge could one day help researchers improve treatments for genetic diseases such as cancer.